LIBRARY 


UNIVERSITY  OF  CALIFORNIA. 


Class 


FOUNDRY  PRACTICE 

A  TREATISE  ON 

MOLDING   AND  CASTING 

IN  THEIR  VARIOUS  DETAILS 


BY 

JAMES   M.   TATE 


• 

AND 


MELVIN  0.   STONE,  M.E. 


PREPARED  FOR  THE  USE  OF  STUDENTS  IN  THE  COLLEGE  OP 
ENGINEERING,  UNIVERSITY  OF  MINNESOTA 


THIRD    EDTION,    REVISED 


OF  THE 

UNIVERSITY 

OF 


NEW  YORK 

JOHN  WILEY  &  SONS 

LONDON:    CHAPMAN  &   HALL,  LIMITED 

1909 


Copyright,  1904,  1909 

BT 

JAMES   M.  TATE 


0,'h*  ^rientifir  |Irrna 
Snhrrt  flrummmtii  and  (Tomjiaati 


INTRODUCTION 

IN  administering  the  work  in  foundry  practice  at  the 
University  of  Minnesota,  the  want  of  a  good  text-book 
has  been  a  serious  disadvantage.  The  work  of  the  shop 
and  that  of  the  class-room  should  be  correlated — shop- 
work  should  be  studied  and  discussed  in  the  class-room, 
and  examples  illustrating  the  various  principles  under- 
lying good  practice  should  be  worked  out  in  the  shop. 

While  there  have  been  some  excellent  books  written 
upon  the  subject  of  foundry  practice,  yet,  as  a  rule,  these 
have  been  written  with  the  needs  of  the  experienced 
molder  in  view  rather  than  those  of  the  beginner.  For 
this  reason  it  is  a  difficult  matter  to  teach  the  subject  so 
that  the  student  will  acquire  an  intelligent  understanding 
of  its  various  details.  The  nomenclature  and  shop  phrase- 
ology are  not  sufficiently  elementary  for  the  average 
beginner  to  grasp  the  statement  presented,  and  much  time 
is  frequently  spent  in  explaining  an  author's  meaning. 

The  present  little  treatise  has  been  written  with  a  full 
knowledge  of  the  problems  involved  and  with  the  object 
of  lessening  some  of  the  difficulties  which  arise  in  teach- 
ing the  subject.  The  authors  are  both  men  of  wide  ex- 
perience in  foundry  practice  and  its  correlated  subjects. 
Mr.  Tate  is  an  experienced  pattern  maker,  who  has  been 
in  charge  of  the  pattern  shop  at  the  University  of  Min- 
nesota for  the  past  fifteen  years,  and  during  a  part  of 
this  time  he  has  also  had  charge  of  the  work  in  the 
foundry.  Mr.  Stone  is  a  graduate  of  the  University, 

iii 

201351 


IV  INTRODUCTION 

who  has  given  especial  attention  to  foundry  work,  both 
from  the  standpoint  of  the  chemist  and  from  that  of  the 
molder. 

In  presenting  this  work  on  foundry  practice,  the 
authors  realize  that  it  is  not  a  complete  treatise  on  the 
subject.  The  aim  has  been  to  produce  a  book  in  which 
the  principles  of  foundry  practice  are  set  forth  concisely 
and  clearly.  The  needs  of  the  engineering  student  rather 
than  those  of  the  practical  foundry  man  were  kept  in  view. 
To  this  end  numerous  examples  are  given  representa- 
tive of  the  different  kinds  of  molding,  and  it  is  believed 
that  the  simple  methods  used  in  illustrating  and  describ- 
ing the  various  operations  involved  and  the  reasons  there- 
for will  give  the  student  a  ready  knowledge  of  the  details 
of  molding  which  will  go  far  to  supplement  the  practical 
work  of  the  foundry,  which,  in  a  college  course,  must 
necessarily  be  limited. 

While  the  treatment  is  thus  somewhat  brief,  the  sub- 
ject matter  as  here  presented  is  intended  to  cover  all 
ordinary  work  in  foundry  practice,  including  both  brass 
and  iron  casting. 

A  glossary  of  foundry  terms  has  been  added,  as  it  has 
been  found  that  to  obtain  the  greatest  value  from  a  work 
of  this  character  the  reader  must  become  familiar  with 
names  and  expressions  used  by  foundrymen,  for  even  if 
it  were  possible  to  eliminate  shop  expressions,  it  would 
be  undesirable  to  do  so. 

J.  J.  FLATHER, 

Professor  of  Mechanical  Engineering, 

MINNEAPOLIS,  MINNESOTA,  UNIVERSITY  OF  MINNESOTA 

September,  1904. 


CONTENTS 

CHAPTER  I 

PAGE 

GREEN  SAND  MOLDING i 

Plain  mold.     Parted  pattern.     Coping  out.     Bedding  in.     Set- 
ting cores.     Check  molding. 

CHAPTER  II 
DRY  SAND  MOLDING 53 

Dry   sand   mixtures.     Venting.     Drying,    finishing,    blacking. 
Skin-drying,  pit  mold,  and  sweeps. 

CHAPTER  III 

MOLDING  SAND,   MOLDER'S  TOOLS,   MOLDING  MACHINES,   AND 

EQUIPMENT 69 

Facing     sand.     Flasks.     Gating.  Gaggers.     Soldiers,     Nails 

and  rods.     Patching.     Stopping  off.  Venting  cores.     Chaplets. 

Setting     chaplets.     Weighting     and  clamping.     Shrink     holes. 

Burning  on,  or  casting  on.     Bench  molding.     Snap-flasks.     A 
match.     Molding  machines. 

CHAPTER  IV 
CORES,  CORE  BOXES,  CORE  MACHINES,  AND  DRYING  OVENS 123 

CHAPTER  V 

CUPOLAS,  BLOWERS,  AND  MELTING  FURNACES  FOR  IRON 151 

Tapping  hole.     Tuyeres.    Charging  door,  hearth.    Slag  notch, 
lining,  charging,  tapping  out.     Ladles,  blowers, 

v 


VI  CONTENTS 

CHAPTER  VI 

PAGE 

CHILLED  CASTINGS 172 

The  chill.     Mixture  of  iron  for  chilled  casting. 

CHAPTER  VII 
MALLEABLE  CASTINGS 176 

The  malleablizing  process. 

CHAPTER  VIII 
CLEANING  CASTINGS iSo 

Hand  work.     Tumbling  barrels,  rattlers.     Sand  blast,  pneu- 
matic hammers,  portable  grinders. 

CHAPTER  IX 

COMPRESSED  Am  FOR  FOUNDRY  PURPOSES 185 

Pneumatic  crane.     Hoist.     Molding  machine,  chipping  ham- 
mer.    Sand  rammer.     Sifter. 

CHAPTER  X 
STEEL  CASTINGS 195 

The  sand  mixture.     The  mold.     The  mixtures  of  metal.     Melt- 
ing and  converting. 

CHAPTER  XI 
BRASS  FOUNDING 199 

Brass   molding.     The   sand.     The   flask.     The   furnace.     Oil 
furnaces. 

CHAPTER  XII 
CAST-IRON  ALLOYS 208 

Tables  for  foundry  use. 

CHAPTER  XIII 
GLOSSARY  OF  FOUNDRY  TERMS 215 


OF  THE 

UNIVERSITY 


FOUNDRY   PRACTICE 


CHAPTER  I 

GREEN  SAND  MOLDING 

THE  method  of  proceeding  in  making  a  mold  for  a 
plain  casting  may  be  demonstrated  by  consideration  of 
the  pattern  shown  in  Fig.  i.  After  having  the  sand 


FIG.  i. 


properly  tempered,  the  turn-over  board  is  placed  on  a 
sand  bed  so  as  to  have  bearing  all  over  to  avoid  rocking 
or  unevenness  of  the  top.  The  pattern  is  then  placed 


FOUNDRY  PRACTICE 


on  the  board  as  shown  in  Fig.  2.     The  drag  may  now  be 
placed  over  the  pattern  and  facing  sand  riddled  onto  the 


FIG.  2. 

pattern.  Cover  the  pattern  with  sand  to  a  depth  of 
approximately  6  inches,  as  shown  in  Fig.  3.  The  sand  is 
rammed  around  the  edge  of  the  flask  with  the  pein  rammer 
by  directing  it  as  shown  at  A,  Fig.  3.  It  is  next  rammed 
around  the  pattern  with  the  rammer  directed  as  shown  at 
B,  Fig.  3.  The  sand  falling  between  these  two  rammings 


FIG.  3. 

is  then  rammed  to  an  even  hardness  sufficient  to  form  a 
firm  body  and  allow  the  free  escape  of  the  gases. 

Care  should  be  taken  in  ramming  to  avoid  striking  the 
rammer  nearer  to  the  pattern  than  one  inch.  Wherever 
the  pein  strikes  the  pattern,  a  hard  spot  is  left  in  the 
sand  which  will  cause  a  scab  on  the  casting.  The  flask 
is  now  filled  full  of  heap  sand  and  rammed  with  the  butt 


GREEN  SAND  MOLDING  3 

rammer,  as  shown  in  Fig.  4^  The  drag  may  now  be 
struck  off  with  a  straight  edge  even  with  its  top.  A  thin 
layer  of  loose  sand  is  then  scattered  over  the  surface  to 
ensure  a  good  bearing  on  the  entire  surface  of  the  bottom 
board.  The  drag  should  now  be  vented  with  one-eighth 
inch  wire  all  around  and  over  the  pattern,  using  care 
not  to  strike  the  pattern  so  as  to  allow  the  metal  to  flow 
into  the  vent.  The  bottom  board  is  placed  onto  the  drag, 
with  care  that  it  bears  on  the  sand  at  all  points.  The 


two  boards  are  clamped  to  the  drag  with  short  clamps, 
iJiown  in  Fig.  5.  The  flask  is  then  turned  over  onto  a  bed 
of  loose  sand,  so  as  to  have  an  even  bearing  at  both  ends. 
The  clamps  are  then  removed  and  the  board  taken  off, 
leaving  the  pattern  at  the  top  of  the  drag.  The  surface  of 
the  joint  is  made  by  tucking  sand  into  any  soft  places  that 
there  may  be,  then  riddle  a  little  loose  sand  on  the  sur- 
face, and  slick  with  a  trowel  so  as  to  make  it  a  little  harder 
than  the  main  body  of  the  sand.  Parting  sand  is  dusted 


4  FOUNDRY  PRACTICE 

over  the  surface  of  the  joint  until  the  entire  surface  is 
covered.    That  falling  onto  the  pattern  is  brushed  off. 


FIG.  5. 

Since  the  flask  is  small  and  the  cope  has  no  bars,  it  may 
now  be  placed  on  and  the  gate  stick  set  even  with  the 
centre  of  the  pattern  and  midway  between  the  flask  and 
pattern,  as  shown  in  Fig.  6.  (This  pattern  having  a  rib 


FIG.  6. 


running  lengthwise,  the  inflowing  metal  should  enter  the 
rib  from  an  end  and  not  over  an  edge.     This  will  reduce 


GREEN  SAND  MOLDING 


the  liability  of  the  metal  cutting  away  the  sand,  causing  a 
bunch  on  the  casting.  A  little  facing  sand  is  riddled  over 
the  pattern,  then  the  heap  sand  is  riddled  through  a  No.  4 
riddle  to  a  depth  of  about  one  inch.  Heap  sand  is  filled 
in  and  rammed  next  to  the  flask  with  the  pein,  then  the 
remainder  is  rammed  to  an  even  hardness.  The  cope  is 
filled  and  rammed  with  the  butt  rammer  and  struck  off 
similarly  to  the  drag.  It  is  vented  over  the  pattern  and 
around  the  gate  stick  with  one-eighth  inch  vent  wire. 


t± 


FIG.  7. 

The  gate  stick  is  loosened  by  rapping  sidewise  and 
withdrawn.  The  hole  is  reamed  out,  leaving  a  large 
opening  to  pour  the  iron  into,  as  shown  in  Fig.\7-  The 
cope  is  ready  to  be  lifted  off  and  placed  on  any  convenient 
rest  where  it  may  be  finished.  The  cope  should  always 
be  finished  before  the  drag  is  touched,  for,  if  anything 
happened  to  necessitate  shaking  it  out,  the  drag  is  ready 
to  have  the  cope  replaced  for  another  ramming.  The 
portion  of  the  cope  that  covers  the  pattern  should  be 
slicked  lightly  with  the  trowel,  then  covered  with  plum- 


6  FOUNDRY  PRACTICE 

bago  with  a  soft  camel's  hair  brush,  or  by  dusting  from  a 
sack  and  then  slicking  with  a  trowel.  The  gate  should  be 
reamed  slightly  to  take  off  the  loose  edge  and  pressed  to 
firmness  with  the  fingers.  The  drag  should  be  brushed 
off  to  remove  the  parting  sand;  then  wet  the  sand  around 
the  pattern  slightly  with  the  swab.  If  the  sand  is  too  wet 
at  any  point  the  metal  will  blow  when  poured,  therefore 


lilt 


FIG.  8. 

care  must  be  exercised  in  putting  on  only  as  much  water 
as  is  necessary  to  make  the  sand  stick  together  well.  The 
pattern  may  now  be  drawn  by  driving  the  draw  spike  into 
the  centre  of  the  pattern,  then  rapping  it  until  the  sand  is 
free  from  the  edges  of  the  pattern;  then  lift  the  pattern 
out  by  slowly  raising  it,  as. shown  in  Fig.  8.  The  mold  is 
slicked  over  lightly  and  patched  in  case  the  pattern  tears 


GREEN  SAND  MOLDING  7 

the  sand  at  any  place.  The  pouring  gate  is  now  con- 
nected to  the  mold  by  cutting  a  runner  from  the  mold  to 
the  gate  of  a  size  that  will  admit  the  iron  freely,  but  it 
must  be  smaller  than  the  portion  of  the  casting  where  it 
connects  so  that  the  runner  may  be  broken  off  easily 
without  damage  to  the  casting.  The  runner  should  be 
smoothed  with  the  fingers  or  a  slicking  tool  to  ensure 


FIG.  9. 

against  loose  sand  being  washed  into  the  mold.  The 
mold  may  now  be  dusted  with  plumbago  and  slicked,  at 
which  time  the  flask  is  ready  to  close.  The  flask  should 
be  clamped  to  provide  against  the  cope  being  lifted  by  the 
metal  and  the  metal  flowing  out  at  the  joint  when  the  mold 
is  poured.  In  clamping  a  flask  it  must  not  be  moved  or 


8 


FOUNDRY  PRACTICE 


jarred,  as  the  sand  hanging  at  the  top  is  liable  to  drop. 
Nor  should  the  cope  and  drag  be  drawn  together  with  a 
great  pressure,  as  the  flask  is  liable  to  give,  causing  the 
sand  to  crush  the  mold  at  the  joint.  The  best  method 
of  putting  on  the  clamps  is  to  have  them  stand  nearly  ver- 
tical and  resting  on  a  wedge  at  the  top.  The  clamp  may 
be  tightened  with  a  clamping  iron  by  catching  the  point 
under  the  clamp  and  on  the  wedge,  then  moving  the  upper 
end  toward  the  clamp,  as  indicated  by  the  arrow  in  Fig~o_. 
The  mold  is  now  ready  to  cast.  / 

The  process  of  making  a  mold  with  a  split,  or  divided 
pattern  is  shown  by  the  small  pulley  in  Fig.  10.     The 


FIG.  10. 


half  of  the  pattern  without  the  dowel-pins  is  placed  on 
the  turn-over  board  and  the  drag  placed  on  it  as  in  the 
previous  case.  The  facing  sand  is  put  on  until  the  arms 
are  covered,  then  heap  sand  is  riddled  through  a  No.  4 
riddle  until  the  centre  is  filled  to  the  top  of  the  rim.  Since 
the  hub  is  deeper  than  the  rim,  there  is  liability  of  the 
sand  crushing  out  when  the  mold  is  poured,  as  the  hub 
fills  to  the  height  of  the  arms  before  the  rim  receives  any 


GREEN  SAND  MOLDING  9 

iron.  To  prevent  the  sand  from  breaking  and  to  hold  it 
together  more  firmly,  wooden  soldiers  are  put  into  the 
sand  between  the  rim  and  the  hub.  The  soldiers  are 
made  of  any  small  pieces  of  wood,  only  large  enough  to 
be  stiff  and  of  a  length  to  reach  beyond  the  pattern  about 
the  same  distance  as  it  is  inserted  into  the  pattern.  They 
are  wet  with  clay  wash,  or  flour  paste,  to  hold  the  sand 
to  the  soldier.  They  are  placed  to  a  depth  of  the  arms 
about  midway  between  the  rim  and  hub,  and  between 
the  arms,  as  shown  in  Fig.  n. 

The  pattern  is  now  completely  covered  with  riddled 
sand  and  the  outside  rammed  as  before.     The  sand  within 


n    n 


FIG.  ii. 

the  pattern  is  rammed  with  any  small  tool  or  iron  rod  that 
can  be  gotten  in  between  the  soldiers  and  the  pattern. 
The  remainder  of  the  drag  is  filled  in,  rammed  and 
vented.  The  flask  may  now  be  turned  over  and  the  joint 
slicked  as  before.  The  other  half  of  the  pattern  is  put 
on  as  shown  in  Fig.  12.  Parting  sand  is  put  over  the 
joint,  then  the  cope  is  placed  in  position.  Pulleys  and 
sheaves  are  generally  poured  from  the  hub,  in  which  case 
the  gate  stick  must  be  placed  above  the  hub.  The  facing 
sand  is  put  on  the  arms  and  hub,  and  riddled  sand  filled 
in  over  the  pattern.  Soldiers  may  now  be  placed  in  the 


IO 


FOUNDRY  PRACTICE 


same  manner  as  in  the  drag,  but  their  office  in  this  place 
is  more  to  hold  the  sand  from  falling  away  when  the  cope 
is  lifted  off  or  closed  after  removing  the  pattern.  The 


FIG.  12. 


first  ramming  is  the  same  as  the  drag,  then  the  gate  stick 
may  be  put  in  place  and  the  ramming  finished.  The 
cope  is  vented,  the  pouring  basin  cut  and  the  gate  stick 
removed,  giving  the  flask  in  form  as  shown  in  Fig.  13. 


FIG.  13. 

The  cope  is  lifted  off  and  placed  on  any  convenient  block- 
ing, as  shown  in  Fig.  14.  The  pattern  in  the  cope  is 
brushed  off  and  lightly  swabbed  with  water. 

The  pattern  is  rapped  and  removed  by  lightly  jarring 
as  it  is  drawn.    The  gate  is  reamed  a  little  at  the  hub  to 


GREEN  SAND  MOLDING 


II 


remove  loose  sand,  then  the  hub  and  arms  are  slicked  and 
blackened  with  plumbago.  The  drag  is  prepared  in  the 
same  manner,  then  the  flask  is  ready  to  close  and  clamp 
for  casting. 


FIG.  14. 

Many  patterns  have  rounded  edges  or  have  the  point 
of  parting  located  at  different  levels  in  various  parts  of 
the  pattern.  In  these  cases  the  parting  on  the  drag  must 
be  shaped  to  allow  the  pattern  to  be  withdrawn  without 
destroying  the  shape  or  tearing  up  the  sand.  The  upper 
portion  of  the  pattern  must  be  formed  in  the  cope.  This 
causes  a  portion  of  the  sand  to  be  hung  in  the  cope  below 
the  level  of  the  flask,  or  the  sand  is  coped  out  to  the  pat- 
tern. In  cases  of  coping  out,  a  portion  of  the  sand  is 
lifted  from  the  pattern  when  the  cope  is  lifted  off.  This 
does  not  admit  of  rapping  the  pattern  or  otherwise  loosen- 
ing the  sand,  therefore  the  sand  must  be  well  anchored 
so  as  to  hold  its  form  well  and  not  require  too  much 
patching. 


12 


FOUNDRY  PRACTICE 


The  pattern  of  the  half  of  an  eccentric  strap,  shown 
in  Fig.  15,  may  be  taken  as  an  example  where  coping  out 
is  necessary.  The  pattern  can  not  be  drawn  sidewise, 
as  the  inner  circle  has  a  flange  on  each  side. 

To  cast  this  eccentric  strap  the  pattern  is  placed  in 
the  drag  with  the  inner  circle  toward  the  turn-over  board, 
then  facing  is  put  on  the  pattern  and  the  drag  filled, 
rammed,  vented,  and  turned  over  as  in  previous  cases. 
The  parting  is  now  made  even  with  the  face  of  the  drag  at 


FIG.  15. 


each  end  up  to  the  edge  of  the  inner  circle.  The  parting 
surface  then  follows  the  outer  edge  of  the  pattern  and  the 
sand  is  sloped  outward  on  each  side,  as  shown  in  Fig.  16. 
This  slope  must  be  so  as  to  allow  the  sand  to  part  freely 
at  all  points  when  the  cope  is  lifted.  The  dry  parting  sand 
is  then  placed  over  the  level  portion  of  the  drag,  but  it 
will  not  stay  on  the  slope.  A  good  way  to  part  that  por- 
tion of  the  mold  is  to  coat  the  surface  with  a  fine,  new, 
sharp  sand,  dampened  so  it  may  be  slicked  on  with  a  tool, 
or  the  fingers ;  then  dust  a  dry  parting  sand  over  this. 

The  cope  for  a  pattern  like  this  must  have  special  bars 
following  near  to  the  shape  of  the  pattern,  as  shown  in 
Fig.  17.  The  bars  must  be  dampened  with  clay  wash  or 
thin  flour  paste  to  make  the  sand  stick  to  the  bars. 


GREEN  SAND  MOLDING 


Facing  is  riddled  onto  the  pattern  and  sand  riddled 
over  the  drag  to  a  depth  of  about  one-half  inch.  The 
flask  joint  is  then  cleared  and  the  cope  is  put  in  place. 
The  gate  stick  is  placed  opposite  the  centre  of  one  end, 
wh.'le  a  riser  is  placed  at  the  other.  The  offices  of  the 
riser  are  to  allow  the  gases  to  escape  from  the  mold,  and 


FIG.  16. 

to  furnish  iron  to  feed  the  casting  when  shrinkage  takes 
place. 

Gaggers  are  then  set  in  the  cope  as  shown  in  Fig  17, 
and  are  placed  near  enough  together  to  anchor  the  sand 
firmly  in  the  cope.  The  sharp  edge  coming  inside  of  the 
flanges  may  be  better  anchored  by  placing  nails  with 
heads  toward  the  pattern  at  intervals  of  about  one  to  two 


!4  FOUNDRY  PRACTICE 

inches.     The  nail  heads  should  be  clay-washed  and  set 
as  soldiers.     Sand  is  now  riddled  into  the  cope  to  a  depth 


FIG.  17. 

of  two  or  three  inches,  then  the  bars  are  tucked  with  the 
fingers  to  harden  the  sand  under  the  bars,  the  same  as  the 


GREEN  SAND  MOLDING  15 

rammed  portion  between  the  bars.  Sand  is  filled  in  to 
a  depth  of  about  six  inches.  The  part  enclosed  between 
each  set  of  bars  is  rammed  separately,  similarly  to  an 
individual  cope,  but  using  care  to  have  all  the  divisions 
rammed  to  an  even  hardness.  The  remainder  of  the  cope 
is  then  filled  in  and  rammed,  having  about  6  to  8  in.  of 
sand  to  a  ramming,  until  the  cope  is  entirely  filled,  when 
it  is  butted  off  and  vented.  In  ramming,  the  operator  must 
avoid  striking  the  gaggers.  as  that  drives  them  into  the 
drag  and  then  necessitates  patching  when  the  cope  is 
lifted  off.  The  cope  may  now  be  lifted  off,  using  care  to 
lift  it  slowly  and  evenly,  in  order  that  the  sand  may  not  be 
torn  by  striking  at  any  point.  The  cope  should  be  gone 
over  with  the  hand  to  see  if  there  are  any  soft  spots, 
which,  when  found,  should  be  filled  to  an  even  hardness 
with  other  parts.  It  is  then  patched  where  necessary  and 
slicked  to  a  smooth  surface.  The  pattern  is  drawn  from 
the  drag  after  removing  all  the  parting  sand  and  swab- 
bing the  sand  at  the  edge  of  the  pattern.  The  mold  is 
slicked  and  the  gate  and  riser  connected  to  the  mold  by 
the  runner.  This  gives  the  mold  in  the  form  as  shown 
in  Fig.  1 8.  The  mold  may  be  blackened  and  closed, 
ready  to  be  cast. 

Many  patterns  are  of  such  form  that  they  require  a 
special  follow-board  or  match  in  order  to  mold  them  by 
turning  over.  When  there  are  not  enough  castings  re- 
quired to  pay  to  make  a  follow-board,  other  means  must 
be  resorted  to.  If  these  are  of  such  form  that  they  may 
be  evenly  rammed  by  bedding  in,  that  method  often  saves 
much  time. 

To  mold  by  bedding  in  is  to  place  the  drag  in  the  posi- 


i6 


FOUNDRY  PRACTICE 


tion  it  is  to  have  when  the  cope  is  put  on,  then  ram  the 
sand  in  until  it  is  of  such  a  height  as  to  bring  the  parting 
of  the  pattern  at  the  parting  of  the  flask,  and  finish  the 
ramming  of  the  drag  with  the  pattern  in  position.  Many 
forms  of  patterns  easily  admit  of  this  method  in  that 
there  are  no  parts  that  are  not  easily  accessible  for  ram- 
ming the  sand  from  the  top  side.  Other  patterns  may  be 
such  that  a  molder  may  easily  patch  any  soft  spots  that 
are  under  the  pattern  when  finishing  the  mold. 


FIG.  18. 

In  some  places  the  main  portion  of  the  molding  is  done 
by  this  method,  but  on  the  majority  of  patterns  it  is 
easier  and  quicker  to  prepare  the  drag  by  turning  it  over. 
In  England,  where  iron  flasks  are  used  the  main  method 
used  is  that  of  bedding  in  due  to  the  weight  and  to  the 
difficulty  in  turning  over  the  flask. 

The  molder  must  use  his  discretion  in  deciding  which 
method  he  should  use,  in  order  to  save  time  and  labor. 
Different  men  making  a  mold  from  the  same  pattern 


GREEN  SAND  MOLDING 


may  be  able  to  do  the  best  and  quickest  work  by  using 
opposite  methods,  according  as  each  is  most  accustomed. 
One  type  of  casting  that  may  best  be  made  by  bed- 
ding in  may  be  illustrated  by  the  making  of  a  large  plain 
plate  by  use  of  the  frame  shown  in  Fig.  19.  The  pat- 
tern is  made  in  frame  so  as  to  be  able  easily  to  ram  the 
sand  which  comes  under  it.  The  narrow  frame  may  easily 
be  tucked  to  the  required  hardness,  while  if  a  solid  pat- 
tern be  used  an  even  hardness  is  much  more  difficult  to 
obtain. 


P  P 


FIG.  19. 

In  making  the  mold  the  drag  is  placed  on  the  bottom 
board  in  the  position  to  receive  the  cope.  Sand  is  shov- 
eled in  and  rammed  to  a  depth  that  will  hold  the  top  of 
the  pattern  nearly  to  a  level  of  the  parting  of  the  flask. 
Sand  is  then  riddled  into  the  drag  to  a  sufficient  depth  for 
putting  the  pattern  in  place  and  tucking  the  sand  firmly 
under  it  The  pattern  is  placed  in  position  and  forced  to 
the  level  of  the  drag,  then  it  may  be  held  by  placing  a 
weight  on  it  to  avoid  raising  while  tucking  sand  under  it 
at  the  soft  places.  The  remainder  of  the  drag  is  rammed 
to  the  parting.  The  drag  is  well  vented  before  making 
the  parting,  thus  closing  the  top  of  the  vents  and  forcing 


l8  FOUNDRY  PRACTICE 

the  gases  out  at  the  bottom  board.  The  cope  is  placed 
on,  rammed,  and  lifted  by  observing  the  precautions 
previously  given. 

In  order  to  make  a  plate  of  the  mold,  the  sand  within 
the  frame  must  be  taken  out  to  a  depth  equal  to  that  of 
the  pattern.  In  order  to  make  this  of  even  depth,  a  strike 
stick,  as  shown  at  A,  Fig.  19,  is  used  to  strike  out  the  sand. 
The  pattern  is  then  removed  and  the  surface  is  slicked 
to  an  evenness,  using  care  not  to  cause  hard  spots.  The 
mold  may  now  be  blackened  and  runners  cut,  when  it  is 
ready  to  close. 

When  a  mold  is  made  in  the  sand  on  the  floor  without 
a  cope  to  cover  it,  it  is  called  open  sand  molding.  This 
is  a  cheap  form  of  molding  for  some  types  of  castings. 
The  casting  will  not  be  clean  or  smooth,  but  may  have 
its  exact  form  all  except  the  upper  surface. 

This  method  may  be  used  for  making  castings  for  parts 
of  iron  flasks,  clamps,  core  irons,  floor  plates,  or  castings 
whose  upper  surface  may  be  rough  and  where  the  exact 
thickness  of  metal  is  not  important. 

Many  of  the  precautions  necessary  to  obtain  a  good 
casting  from  open  sand  work  may  be  noted  in  the  pro- 
cedure for  making  the  flask  bar  shown  in  Fig.  20.  The 
manner  of  making  molds  of  this  style  varies,  as  is  most 
convenient  with  the  material  the  molder  has  at  hand. 
The  method  given  below  is  most  flexible  and  may  be  used 
on  a  great  variety  of  patterns.  Particular  cases  may  be 
handled  in  very  different  manner. 

The  top  surface  of  the  pattern  must  be  level  in  all  direc- 
tions, for  the  metal  when  poured  is  a  liquid  which  seeks 
its  level.  The  metal  lies  on  the  sand  with  only  the  thick- 


GREEN  SAND  MOLDING  19 

ness  of  the  casting.  Since  there  is  no  head,  as  in  gates 
and  risers,  to  give  a  pressure,  the  sand  must  be  open  and 
well  vented  to  give  a  free  escape  to  the  gases;  or  they  will 
force  through  the  iron  and  cause  the  sand  to  cut  away, 
making  a  bunch  on  the  casting,  or  leaving  blow-holes 
through  the  iron. 

The  pattern  here  shown  has  the  lower  face  a  plane  ex- 
cept for  the  flanges  at  each  end.  We  may  therefore 
make  a  level  bed  and  place  the  pattern  onto  it.  To  make 
the  bed  two  straight  pieces,  preferably  T-rails,  are  placed 
on  the  floor  and  leveled.  One  piece  is  placed  down  and 


FIG.  20. 

leveled  with  a  spirit  level,  then  the  other  is  laid  parallel 
with  it  at  a  distance  that  will  give  ample  room  to  locate 
the  pattern,  with  the  pouring  basin  coming  at  the.  edge  of 
the  bed.  This  piece  is  made  level  with  the  first  by  use  of  a 
straight  edge  resting  on  each  piece  and  the  level  on  the 
upper  parallel  edge  of  the  straight  edge.  Sand  is  filled  in 
almost  to  the  top  of  the  pieces  and  rammed  lightly  to  an 
even  hardness.  The  remainder  is  filled  with  riddled  sand 
and  struck  off,  having  pieces  about  f  inch  in  thickness 
between  the  strike  stick  and  the  rails.  To  ram,  the  rails 
are  cleared,  then  by  holding  the  strike  stick  firmly  on  its 


20  FOUNDRY  PRACTICE 

edge  on  one  rail  and  striking  down  with  the  other  end 
until  the  sand  is  compressed  to  the  level  of  the  rails.  This 
ensures  even  hardness.  Unless  the  sand  is  very  open,  the 
bed  should  be  well  vented  downward  with  cross  vents, 
allowing  the  gas  to  escape  to  the  sides.  The  bed  is  then 
struck  off  with  a  straight  edge  resting  on  the  leveled 
pieces,  thus  giving  an  even  and  level  bed. 

The  pattern  is  then  placed  on  the  bed  in  the  position 
most  convenient  for  pouring.  It  may  be  driven  down 
part  the  depth  of  the  flange,  then  drawn  out  and  the  de- 
pression of  the  flanges  cut  with  a  trowel  to  soften  the 
sand,  to  avoid  its  becoming  too  hard  when  the  pattern  is 
forced  down  to  the  bed.  The  pattern  is  replaced  and 
forced  down  to  a  bearing  on  the  bed.  The  edges  may 
then  be  tucked  a  little  to  harden  the  sand  on  which  the 
edges  rest.  Sand  is  filled  in  and  tucked  with  the  hands 
around  the  pattern  until  the  sand  is  above  its  top. 
The  top  is  struck  off  even  with  the  pattern  by  any  short 
straight  edge,  and  the  surface  slicked  with  a  trowel. 
The  pouring  basin  may  be  built  at  the  end  by  mak- 
ing a  U-shaped  mound  of  sand  with  the  enclosed  por- 
tion tapering  down  away  from  the  edge  of  the  pattern. 
The  object  of  this  depression  is  to  hold  some  metal  on 
which  the  inflowing  metal  strikes  instead  of  on  the 
sand. 

The  pattern  may  be  removed  from  the  mold  after  swab- 
bing the  edge  and  rapping  to  free  the  sand.  The  bottom 
is  slicked  smooth  with  the  trowel,  care  being  used  not  to 
make  hard  spots.  The  flange  may  be  patched  to  proper 
shape  whenever  necessary,  then  the  mold  is  ready  to  re- 
ceive the  metal. 


Of    THE     " 

UNIVERSITY 

OF 


REEN  SAND  MOLDING  21 


In  the  case  of  coring  holes  through  the  plate,  the  prints 
may  be  on  the  lower  side  of  the  pattern  when  placed  on 
the  bed.  The  cores  near  to  the  entering  metal  should  be 
supported  by  nails  to  avoid  washing  out  by  the  flow  of  the 
metal.  It  is  a  good  plan  to  put  a  few  nails  at  the  edge 
next  to  the  basin  to  prevent  its  breaking  in  when  poured. 

Many  castings  require  dry  sand  cores  for  making  holes 
and  openings  in  the  castings  that  are  solid  in  the  pattern. 
In  these  cases  the  pattern  has  a  print  which  locates  the 
core  and  holds  it  in  position  in  the  mold.  The  core  must 
be  vented  off  in  the  mold  to  allow  the  gases  to  escape 
freely.  It  must  be  properly  anchored  by  bearing  on  the 
sand  or  by  chaplets  to  prevent  its  floating  when  the  iron 
surrounds  it  in  pouring. 

Some  of  the  principles  involved  in  setting  cores  are 
illustrated  in  making  the  casting  shown  in  Fig.  21.  This 
is  the  casing  for  a  theadstock  whose  body  part  is  hollow 
and  having  the  bearings  cored  for  babbit. 

The  pattern  used  is  shown  in  Fig.  22.  This  is  a  one- 
part  pattern  having  loose  pieces  for  the  projecting  parts. 
In  this  case  the  loose  pieces  are  held  in  place  by  a  dove- 
tail. Usually  loose  pieces  are  pinned  onto  the  pattern. 
In  cases  where  loose  pieces  are  pinned  on,  the  sand  is 
rammed  around  the  loose  piece,  then  the  pin  is  drawn, 
leaving  it  free  from  the  pattern  when  it  is  withdrawn  from 
the  mold. 

The  drag  and  cope  are  rammed  in  the  usual  manner  of 
a  common  mold.  When  the  pattern  is  drawn  from  the 
drag,  the  loose  pieces  remain  in  position  in  the  sand,  as 
at  A,  Fig.  23.  The  mold  should  be  patched  and  finished 
before  drawing  the  loose  pieces.  The  edge  of  the  large 


22 


FOUNDRY  PRACTICE 


FIG.  21. 


FIG.  22, 


GREEN  SAND  MOLDING 


pieces  should  be  nailed  with  short  nails  to  prevent  tearing 
or  dropping  when  the  piece  is  removed.  The  nails  should 
be  slanted  away  from  the  pattern  and  pressed  in  so  the 
head  comes  even  with  the  surface.  The  loose  piece  is 
then  loosened  from  the  sand  by  rapping,  and  drawn  into 
the  mold,  as  at  B,  Fig.  23.  These  new  parts  are  then 
finished  and  the  mold  may  be  blackened  all  over. 

The  cores  are  placed  into  the  mold  after  the  manner 
shown  in  Fig.  24.     The  cores  are  vented  off  at  the  bottom 


m 


FIG.  23. 

by  running  a  vent  wire  down  from  the  print,  then  insert- 
ing another  wire  on  the  bottom  board  to  strike  the  former. 
Several  vents  must  be  made  in  this  manner  to  ensure  free 
escape  of  the  gases.  This  being  a  compound  core,  those 
at  the  bottom  must  be  set  first.  The  small  bearing  cores 
go  into  the  opening  left  by  the  print  on  the  loose  pieces  A 
and  B,  Fig.  23.  The  main  core  has  a  bearing  on  each  of 
these  cores  and  is  held  in  place  by  the  side  of  the  mold 
which  was  formed  by  the  main  print  of  the  pattern. 


FOUNDRY  PRACTICE 


The  upper  vents  of  the  core  should  be  closed  with  sand 
or  flour  to  prevent  the  metal  flowing  into  the  vent  if  it 
should  get  above  the  core.  The  print  in  the  cope  holds 
the  upper  side  of  the  core  in  position,  thus  preventing  the 
liability  of  moving  sidewise  when  the  mold  is  cast.  The 
mold  may  be  closed  when  the  gates  and  runners  are 
properly  cut. 

Many  patterns  are  of  such  form  that  they  can  not  be 
drawn  from  a  two-part  flask,  in  which  case  an  intermedi 


rf 


FIG.  24. 

ate  portion  called  a  cheek  is  required.  This  branch  of 
molding  is  generally  known  as  three-part  work.  The 
flask  used  and  the  methods  of  procedure  are  dependent 
upon  the  pattern.  These  are  greatly  varied. 

To  illustrate  one  of  the  general  forms  using  a  "plain 
cheek,"  we  have  taken  for  an  example  the  piston  spider 
for  a  Corliss  engine,  shown  in  Fig.  25.  The  pattern,  as 
shown  in  Fig.  26,  is  in  two  parts.  The  main  or  body  con- 
sists of  the  outside  ring  as  shown  in  the  figure.  The 
other  portion  consists  of  the  centre  hub  with  web  con- 


GREEN  SAND  MOLDING 


necting  it  to  the  ring.     The  bosses  in  the  pockets  are 
loose  and  pinned  onto  the  body  portion  of  the  pattern. 


FIG.  25. 


FIG.  26. 


To  ensure  a  firm,  clean  casting,  it  is  advisable  in  this 
case  to  run  some  metal  through  the  mold  after  it  is  filled. 


26  FOUNDRY  PRACTICE 

The  mold  is  poured  from  the  bottom,  thus  providing  a 
skim  gate  and  allowing  the  metal  to  rise  in  the  mold  with- 
out flowing  across  the  overhanging  portion  of  the  cheek. 

To  form  the  mold,  the  pattern  is  placed  on  the  follow- 
board  with  all  the  parts  in  place.  Facing  sand  is  put  into 
the  pockets  to  a  depth  of  about  2  in.  Long  rods  are 
placed  in  the  pockets  to  securely  anchor  them  in  the  cope. 
Fill  in  about  2  in.  more  of  facing  and  ram  lightly  with  a 
rod  or  stick,  using  care  to  avoid  making  the  sand  too  hard. 
The  remainder  of  the  pocket  is  filled  and  rammed.  The 
pins  may  be  removed  from  the  bosses.  The  pockets 
should  now  be  thoroughly  vented,  using  a  needle  wire 
smaller  than  TV  in.  in  diameter. 

The  cheek  may  be  placed  on  the  follow-board  about 
the  pattern.  The  gate  stick  is  placed  in  its  position  out- 
side of  the  pattern.  The  cheek  is  now  rammed  and  the 
parting  made  at  the  upper  edge  of  the  ring.  The  cope 
may  be  placed  upon  the  cheek.  The  pouring  gate  from 
the  cheek  extends  through  the  cope,  and  a  flow-off  gate  is 
placed  on  the  centre  hub  beside  the  centre  core.  The  cope 
is  rammed,  ensuring  proper  anchorage  for  the  rods  from 
the  pockets.  It  should  be  well  vented,  especially  above 
the  pockets.  The  gate  sticks  are  then  removed.  A 
bottom  board  is  placed  upon  the  cope,  the  flask  firmly 
clamped  together,  and  the  whole  turned  over.  The  fol- 
low-board is  removed  and  the  lower  parting  made  on  the 
cheek. 

The  core  print  is  placed  on  the  pattern.  The  drag  is 
rammed,  having  proper  anchorage  for  lifting  it  off.  After 
venting  the  drag  is  lifted  off  and  placed  on  a  bottom 
board  bedded  for  receiving  the  flask.  The  drag  is  slicked 


GREEN  SAND  MOLDING  27 

and  finished.  The  surface  directly  in  front  of  the  gate 
is  nailed  to  prevent  the  iron  from  cutting  away  the 
sand. 

The  body  portion  of  the  pattern  is  drawn  from  the 
flask.  The  top  of  the  cheek  is  finished  and  the  runner 
cut  to  connect  with  the  pouring  gate.  The  cheek  is  lifted 
off  and  completely  finished  and  blackened,  then  placed 
in  its  position  on  the  drag.  Before  removing  the  second 
portion  of  the  pattern  from  the  cope,  the  edges  of  the 
pockets  should  be  well  nailed  to  better  anchor  the  sand. 
The  pattern  may  now  be  drawn  and  the  cope  finished  and 
blackened.  After  setting  the  centre  core,  the  flask  may 
be  closed.  The  gate  sticks  are  replaced  in  their  respec- 
tive positions,  in  order  to  form  the  overflow  runner  and 
the  pouring  basin,  which  must  be  higher  than  the  flow-off 
gate.  To  prevent  closing  the  vents  in  the  cope,  when  the 
flow-off  gate  is  made,  the  surface  is  covered  with  paper, 
hay,  or  any  convenient  material.  The  gate  is  made 
with  a  runner  to  conduct  the  overflow  from  the  flask. 
After  clamping  it  is  ready  to  receive  the  metal. 

In  some  cases  it  is  found  that  dirt  accumulates  in  the 
flange  directly  above  the  gate  where  the  metal  enters.  It 
acts  as  a  whirl  or  retaining  point  that  is  not  forced  to  cir- 
culate as  the  metal  is  flowing  into  the  mold.  To  avoid 
this,  it  is  advisable  to  put  a  top  gate  on  the  opposite  side 
of  the  centre  core  from  the  flow-off  gate. 

Many  forms  of  patterns  requiring  three-part  flasks  are 
such  that  the  "cheek  can  not  be  lifted."  In  such  cases 
the  lower  portion  of  the  pattern  is  drawn  and  that  part  of 
the  mold  finished  before  the  drag  and  cheek  are  rolled 
over. 


28 


FOUNDRY  PRACTICE 


The  lathe  bed  casting  shown  in  Fig.  27  gives  a  good 
example  of  this  class  of  work.  The  pattern  has  the  two 
upper  rails  loose  with  the  fillets  attached  forming  the 

guides  to  hold  them  in  place. 

[  rr:pr:  This  casting  may  best  be  gated  so  as  to  allow 

the  metal  to  enter   at  both  top   and  bottom 
1  rails,  thus  reducing  the  liability  of  the  metal 

^        cutting,  from  too.  great  a  flow  at  the  bottom  or 
by  falling  from  the  top  of  the  mold. 

The  cheek  is  placed  on  the  follow-board  and 
the  pattern  placed  with  the  cope  side  down, 
in  which  case  the  loose  rails  come  on  the 
.  upper  side.  The  gate  stick  is  placed  in  posi- 
tion so  that  runners  may  be  cut  to  the  lower 
rails.  The  pattern  is  then  faced  on  the  out- 
side and  rammed  in  the  usual  manner.  The 
inner  portion  will  be  a  green  sand  core  which 
is  separate  from  the  flask  and  has  bearing  at 
top  and  bottom.  In  the  centre  of  each  should 
be  placed  a  vent  rod  to  give  an  opening  for 
carrying  off  the  gases.  The  sand  is  filled  in 
and  rammed  to  a  depth  of  about  four  inches. 
Rods  are  now  laid  in  diagonally  to  bind  the 
sand  together.  Use  facing  next  to  the  pattern 
and  riddled  sand  for  the  remainder.  Each  succeeding 
ramming  of  from  2  to  4  in.  should  be  well  rodded  laying 
them  in  different  directions  each  time.  When  the  cross 
webs  of  the  pattern  are  covered,  it  is  best  to  place  two 
or  three  long  rods  in  to  bind  the  whole  core  together. 

When  the  cheek  is  finished  the  parting  is  made  even 
with  the  top  of  the  pattern.  The  face  of  this  parting 


GREEN  SAND  MOLDING  29 

should  be  harder  than  in  the  previous  cases,  because  the 
pressure  head  of  the  metal  is  very  great  as  this  comes 
at  the  bottom  of  the  mold.  A  good  method  of  getting 
this  parting  of  even  hardness  is  to  riddle  some  sand  onto 
the  surface  to  a  depth  of  about  2  in.,  then  butt  in  firmly 
but  not  hard. 

Strike  it  off  with  a  stick,  then  slick  with  a  trowel  after 
riddling  on  a  little  sand  over  the  entire  surface.  The 
gate  stick  should  come  to  this  surface  but  not  extend 
beyond.  Parting  sand  is  put  on  and  the  drag  rammed, 
vented  and  lifted  off. 

The  cheek  should  be  well  vented  on  the  outside  of  the 
pattern  and  under  the  rail  that  is  about  to  be  drawn. 
These  vents  should  be  led  off  to  the  parting  of  the  flask. 
The  centre  portion  should  have  vent  gutters  cut  around 
within  about  2  in.  of  the  pattern  and  leading  to  the  centre 
vent  rod  of  each  of  the  cores.  The  vents  are  all  made  to 
extend  from  this  gutter.  The  wire  should  be  |  or  T%  in. 
in  diameter.  Vent  particularly  under  the  rails  and 
around  the  centre  web. 

The  parts  of  the  pattern  are  drawn.  The  edges  of  the 
fillets  near  the  web  or  the  part  of  the  pattern  still  remain- 
ing in  the  mold  should  be  nailed,  using  tenpenny, nails  and 
placing  them  about  2  in.  apart.  The  mold  is  then  slicked, 
blackened,  and  gates  cut  from  the  rails  to  the  gate  stick. 
The  drag  is  then  closed  onto  the  cheek.  Sand  should  be 
thrown  onto  the  top  and  struck  off  evenly.  This  may  be 
easily  accomplished  by  using  a  straight  edge  with  a  gagger 
or  strip  of  wood  under  it  and  bearing  on  the  flask.  The 
bottom  board  is  placed  on  and  rubbed  to  good  bearing, 
then  the  flask  is  clamped  together  firmly  and  turned  over, 


30  FOUNDRY  PRACTICE 

using  care  not  to  strain  the  mold.  The  follow-board  is 
removed  and  the  upper  parting  made  on  the  cheek. 

The  cope  is  then  rammed,  having  a  riser  opposite  the 
gate  and  the  vent  rods  drawn  up  to  give  opening  through 
the  cope.  This  is  lifted  off  and  finished  in  the  usual 
manner.  The  cheek  is  vented  under  the  rails  on  the  out- 
side of  the  pattern  and  the  vents  led  off  to  the  parting. 
In  venting,  do  not  endanger  forcing  the  wire  into  the 
lower  part  of  the  mold  where  the  pattern  has  been  re- 
moved. In  the  centre  portion,  vent  gutters  should  be  cut 
around  each  core  and  led  to  the  centre  vent;  then  vent  the 
core  to  lead  to  these  gutters.  The  pattern  may  now  be 
drawn  and  the  mold  slicked  and  blackened.  Runners 
are  cut  to  connect  the  rails  to  the  main  gate.  The  cope 
may  be  closed,  the  pouring  basin  made,  and  the  riser 
built  to  the  same  height. 

In  this  mold  there  is  a  depth  of  metal  which  causes  a 
pressure  against  the  side.  This  must  be  provided  for  in 
clamping  the  mold.  A  tie  clamp  may  be  placed  over  the 
flask,  having  the  parallel  ends  long  enough  to  reach  to  the 
bottom  of  the  cheek.  Wedges  are  placed  between  the 
clamp  and  the  flask,  and  forced  to  a  firm  bearing,  but 
must  not  spring  the  flask.  These  may  be  driven  in  hard 
enough  by  striking  with  a  hammer  handle.  In  these 
cases,  be  very  careful  not  to  put  great  pressure  at  the 
sides,  for  the  flask  will  be  forced  together,  making  the 
metal  of  the  web  too  thin  or  causing  the  cheek  to  cut 
through  the  core. 

In  making  many  castings  much  time  may  be  saved  by 
making  "three-part  work  in  two-part  flasks."  This  may 
be  accomplished  by  using  a  cover  core  over  the  bottom 


GREEN  SAND  MOLDING 


31 


division  of  the  mold  when  that  is  a  plane  surface.  In 
other  cases  the  cheek  portion  may  be  made  in  the  sand 
alone.  This  latter  form  may  be  shown  by  the  sheave- 


C 


FIG.  28. 


wheel  made  from  the  pattern  shown  in  Fig.  28.     There 
are  two  other  methods  of  making  this,  and  the  method 


rr 


FIG.  29. 

chosen  depends  mainly  upon  the  size  of  the  wheel  to  be 
made.  Fig.  29  represents  a  three-part  flask  with  the 
cheek  so  it  may  be  lifted.  Fig.  30  is  a  two-part  flask 


32  FOUNDRY  PRACTICE 

having  the  third  or  cheek  made  in  core.  After  the  pat- 
tern is  drawn  out,  cores  of  the  form  shown  at  A  are  set  in 
the  place  of  the  print  on  the  pattern.  This  method  is  of 
great  convenience  when  there  are  two  or  more  grooves  in 
place  of  the  single  groove  here  represented. 
The  pattern  is.  made  in  halves,  as  shown  in  Fig.  28.  The 


FIG.  30. 

process  of  molding  would  be  to  ram  the  cope  as  usual 
with  the  pattern  in  the  centre  of  the  flask,  as  shown  in 
Fig.  31,  having  the  gate  stick  placed  on  the  hub.  The  flask 
is  turned  over  and  the  parting  made  to  slope  down  to  the 
parting  line  of  the  pattern,  as  shown  in  Fig.  32.  The 
other  half  of  the  pattern  is  put  in  place  and  weighted  so  as 
to  ensure  its  remaining  in  place  while  the  cheek  is  made. 


GREEN  SAND  MOLDING 


33 


The  cheek  is  made  by  tucking  in  about  the  pattern  until 
filled,  so  as  to  make  the  upper  parting  as  shown  in  Fig.  33. 


•:|||^- ,  -         |  j  :5| 


FIG.  31. 

The  drag  may  now  be  put  in  place  and  rammed.     It  must 
be  sufficiently  anchored  to  allow  lifting  off. 


FIG.  32. 

The  drag  is  then  lifted  off  and  that  half  of  the  pattern 
drawn  and  the  mold  slicked  and  finished,  as  shown  in 


FIG.  33. 

Fig.  34.    The  drag  is  replaced    and  the  bottom  board 
given. a  firm  bearing  by  use  of  loose  sand  on  the  flask, 


34 


FOUNDRY  PRACTICE 


then  turned  over  carefully  onto  the  bed  where  it  is  to  re- 
main. The  cope  is  now  lifted  and  the  remainder  of  the 
pattern  drawn  and  the  mold  finished.  In  lifting  a  part 
of  the  flask  where  the  pattern  is  lifted  with  it,  a  draw  spike, 
or  wood  screw,  should  be  put  into  the  pattern  and  held 
when  the  flask  is  lifted.  The  centre  core  is  set,  then  the 
mold  may  be  closed:  A  pouring  basin  should  be  built 
on  the  runner  so  that  the  iron  may  strike  in  the  basin  in- 


FIG.  34. 

stead  of  directly  into  the  gate.  This  breaks  the  fall  of 
the  iron  from  the  ladle  and  relieves  the  straining  pressure 
on  the  mold,  besides  acting  as  a  skim  gate  when  the  basin 
is  kept  full.  The  dirt  and  slag  float  on  top,  while  the 
clean  metal  enters  the  mold  from  the  bottom  of  the  basin. 
This  gives  the  mold  as  shown  in  Fig.  35. 

The  use  of  cores  for  covering  part  of  the  mold  instead 
of  a  third  part  to  the  flask  is  found  to  be  of  great  advan- 
tage when  making  large  base-plates  for  columns.  Fig.  36 


GREEN  SAND  MOLDING 


35 


FIG.  35. 


Ih-B 


FIG.  36. 


36  FOUNDRY  PRACTICE 

shows  a  base-plate  casting  which  may  be  made  by  use  of 
cover  cores. 

The  pattern  for  this  casting  has  the  top  and  bottom 
pieces  doweled  to  the  centre  piece  and  the  ribs,  while  the 
ribs  are  also  separate  from  one  another.  The  pattern  in 
its  complete  form  is  placed  on  the  follow-board  in  the 
drag.  The  bottoms  of  the  pockets  are  faced  and  filled 
with  sand  to  a  depth  of  about  3  in.  This  is  rammed 
lightly,  then  long  rods  are  laid  in  horizontally,  extending 
out  to  the  flask.  Two  rods  should  be  placed  in  near  the 
corner  of  each  pocket  and  slanting  upward  to  just  allow 
room  for  the  cores  to  be  placed  on  the  top  without  strik- 
ing the  rods.  These  rods  should  not  strike  the  pattop. 
The  buoyancy  of  the  metal,  acting  on  the  bottom  of*he 
sand  which  forms  the  pocket,  is  held  by  these  rods  placed 
in  the  sand.  This  buoyancy,  or  lifting  force,  acts  on  the 
surface  exposed  by  the  lower  plate  proportionally  to  the 
area  exposed  and  the  height  of  the  pressure  head.  About 
3  or  4  in.  of  sand  is  filled  into  the  pockets  and  rammed 
abouc  the  rods  with  a  small  rammer,  care  being  used  to 
have  the  rods  firmly  rammed  into  place  and  not  sprung 
so  as  to  tear  the  mold  when  the  pattern  is  drawn.  The 
sand  should  be  well  vented  in  the  pockets  and  a  coke  bed 
for  collecting  the  gases  laid  into  the  pockets  and  leading 
to  the  flask  where  the  gases  may  escape.  The  coke  bed 
is  covered  with  sand  to  a  depth  for  ramming,  then  a 
number  of  rods  should  be  laid  in  horizontally  as  before. 

Much  time  may  be  saved  in  molding  if  cores  are  made 
to  fit  the  pockets  next  to  the  top  plate  and  of  a  thickness 
of  about  2  in.  These  cores  should  extend  out  to  a  dis- 
tance of  3  in.  beyond  the  plate  B.  This  prevents  the 


GREEN  SAND  MOLDING  37 

green  sand  from  breaking  when  turned  over.  The  sand 
below  the  cores  should  be  well  vented  to  the  coke  bed 
and  have  a  firm,  even  bearing  all  over.  When  no  cores 
are  used,  rods  should  be  laid  in  near  to  the  plate  and  the 
sand  well  rammed  and  vented  to  the  coke  bed.  After  re- 
moving the  plate  the  edges  should  be  well  nailed  before 
replacing  the  cover  core. 

The  flask  is  now  filled  'to  the  plate  B.  This  is  left  in 
place  and  sand  rammed  in  and  a  surface  made  even  with 
the  top  of  pattern.  When  a  special  cover  core  is  used, 
it  should  be  put  in  place  determined  by  the  centre  print 
and  the  edges  marked  in  the  sand  and  guide  rods  placed 
at  the  corners  to  ensure  replacing  to  the  proper  position. 
The  core  is  now  lifted,  the  pattern  drawn  and  the  mold 
finished  in  this  portion.  The  cover  core  is  replaced  and 
the  remainder  of  the  drag  filled,  rammed,  and  vented, 
ready  to  turn  over. 

When  no  special  cover  core  is  provided,  an  extra  piece 
may  be  made  for  the  pattern  coming  to  the  edges  marked 
C  in  the  figure.  This  may  be  drawn  from  the  other  side 
of  the  mold.  In  this  case,  after  the  surface  is  made  even 
with  the  top  of  the  pattern,  the  plate  B  is  drawn  and  this 
piece  is  placed  on  the  pattern  with  the  centre  print. 
Stock  slab  cores  may  be  used  to  cover  the  mold  in  the 
place  of  the  cover  core. 

The  drag  is  turned  over,  the  parting  made,  and  the 
cope  rammed,  having  a  gate  at  the  centre  of  one  side  and 
a  riser  at  another  side.  The  large  plate  A  is  drawn  first 
and  the  faces  of  the  pockets  finished.  The  front  corners 
should  be  nailed  with  large  nails  and  a  few  placed  along 
the  sides  to  prevent  the  sand  from  cutting,  cracking  off, 


38  FOUNDRY  PRACTICE 

or  scabbing  when  the  mold  is  poured.  The  ribs  may  be 
drawn  separately  and  the  centre  square  last.  The  gate 
should  be  cut  opposite  the  ribs,  thus  reducing  to  a  mini- 
mum the  liability  of  cutting. 

When  the  bottoms  of  the  pockets  overhang  quite  a  dis- 
tance, it  is  advisable  to  put  double-end  chaplets  between 
the  core  at  the  bottom  of  the  pocket  and  the  cover  core. 
This  takes  the  weight  of  the  core  and  prevents  it  from 
sagging  when  the  flask  is  turned  over.  The  lifting  pres- 
sure may  be  greater  than  will  be  held  by  the  rods  that  are 
placed  in  the  pockets.  In  this  case,  a  plate  of  thin  cast 
iron  may  be  placed  on  the  top  of  the  pocket  and  a  chaplet 
run  through  the  cope  to  bear  on  this  plate.  The  chaplet 
should  be  wedged  only  tight  enough  to  prevent  giving,  but 
not  so  as  to  endanger  cracking  the  green  sand.  Another 
manner  of  chapleting  these  pockets  is  to  use  a  double- 
end  chaplet  with  plates  on  both  sides  or  very  large  heads. 
The  chaplets  should  be  such  that  the  distance  between 
the  two  outer  faces  exactly  equals  the  thickness  of  the 
plate  A.  The  plates  on  the  chaplets  are  necessary  since 
they  bear  on  green  sand,  and  small  heads  would  cut 
through  without  offering  much  resistance. 

Pulleys  having  a  face  of  any  desired  width  may  be 
made  by  use  of  a  pattern  ring  which  is  drawn  up  in  mold- 
ing to  the  width  desired.  The  pattern  consists  of  a  pat- 
tern ring,  as  shown  in  Fig.  37,  the  arms  with  the  desired 
hubs,  and  the  core  prints.  Making  the  hub  separate 
from  the  arms  allows  putting  any  sized  hub  desired  onto 
the  one  set  of  arms. 

The  mold  is  made  by  the  method  of  bedding  in.  The 
drag  is  placed  on  the  bottom  board  and  rammed  with 


GREEN  SAND  MOLDING 


39 


sand  nearly  to  the  height  that  the  pattern  ring  should 
be  placed.  Riddled  sand  is  put  in  to  a  height  such  that 
the  ring  will  bed  into  it.  The  ring  is  then  bedded  down 
to  such  a  distance  that  the  width  of  the  ring  plus  the  dis- 


FIG.  37. 

tance  A,  Fig.  38,  will  equal  the  desired  width  of  face  plus 
the  finish  on  the  pulley.  The  sand  is  then  rammed 
around  the  ring  nearly  to  its  top.  This  should  be  well 


FIG.  38. 

vented  all  over  before  drawing  up.  The  ring  is  then 
drawn  up  about  2  in.  by  placing  blocks  at  three  or  four 
points  about  the  rim  and  extending  above  the  ring  an 
even  height  on  each  one.  This  keeps  the  ring  even  when 


40  FOUNDRY  PRACTICE 

drawn  to  a  level  of  the  blocks  each  time.  In  ramming, 
the  sand  must  not  be  too  hard  about  the  ring  or  the  iron 
will  not  run  the  rim  full.  Usually  direct  the  rammer 
slightly  away  from  the  ring  rather  than  toward  it. 

The  arms  should  be  positioned  when  the  ring  has  been 
drawn  to  half  the  width  of  the  face  of  the  required  pulley. 
The  arms  are  bedded  in  and  the  parting  made  from  the 
centre  line .  of  the  arms  having  the  sand  between  them 
come  to  a  level  of  their  top,  giving  the  flask  as  shown  in 


L_ 

_1 

. 

A 

; 

1 

fe^iMl 

m 

'/fltftf^//,                                  ^^^^^^^ 

4X'V 

i&&3  ' 

IHHHifS^^^^SBSSI 

'  •:    5i 

• 

: 

m 

;;Hx^;S-^i& 

^:>N^sVv.--^--v  •                         £  ;f.V>\;v,^^,:^-.,^;.^^r-_ 

:s^':' 

, 

„>'.-•. 

: 

^^^^^^j^^^i^^^S^^^^^^Ell^ii^; 

1 

LJ 


FIG.  39. 


Fig.   39.     This   is   to  prevent  having  a  heavy  body  of 
sand  hanging  below  the  anchor. 

Sand  is  riddled  over  the  parting  and  the  anchor  placed 
in  position.  The  anchor,  as  shown  in  Fig.  40,  has  the 
three  nuts  for  the  screw  eyes  which  are  for  lifting  the 
anchor.  These  screw  eyes  are  left  in  place  until  after  the 
cheek  is  rammed,  then  they  are  removed  and  the  holes 
covered  for  ramming  the  cope.  The  outer  circle  of  the 
anchor  must  be  smaller  than  the  inside  of  the  ring  to  allow 
for  the  contraction  of  the  rim  when  cooling.  Pieces  should 
be  put  in  to  guide  the  anchor  back  to  the  same  position 
after  removing  from  the  mold.  These  may  be  short  cones 


GREEN  SAND  MOLDING 


or  square  pryamids.  They  are  placed  in  two  or  three 
places  between  the  arms  and  extending  below  the  parting. 
They  are  fastened  so  as  to  ensure  remaining  firm  in  the 
anchor.  These  pieces  are  often  called  pulley  feet.  Around 
the  edges  of  the  anchor  nails  should  be  placed  to  extend 
nearly  to  the  pattern  and  firmly  anchor  the  sand  about  the 
edges  and  the  arms.  The  remainder  is  filled  in,  rammed, 
and  the  pattern  drawn  until  the  parting  is  reached  at  the 


FIG.  40. 

top  of  the  drag.  Two  small  gate  sticks  are  placed  on  the 
hub  for  admitting  the  metal.  The  flask  is  ready  for  form- 
ing the  parting,  as  shown  in  Fig.  41,  and  for  placing  on  the 
cope  for  ramming. 

The  cope  is  rammed,  having  the  two  centre  gates,  a 
riser  on  the  rim,  and  a  vent  opening  from  the  cheek.  The 
cope  is  lifted  and  finished. 

The  vent  gutter  is  cut  around  the  outside  of  the  cheek 
within  about  2  in.  of  the  ring  and  connecting  with  the  vent 


42  FOUNDRY  PRACTICE 

opening  in  the  cope.  Slant  vents  lead  to  the  gutter  from 
all  parts  of  the  cheek.  The  outside  is  vented  and  led  to 
the  parting  of  the  flask.  In  venting  the  wire  must  not  be 
forced  deeper  than  the  pattern  ring,  because  it  would 
break  away  the  face  of  the  mold.  The  pattern  ring  is 
drawn  out  and  the  screw  eyes  are  replaced  into  the  anchor 
and  the  cheek  lifted  out.  The  arms  may  then  be  drawn, 
giving  the  mold  in  parts,  as  shown  in  Fig.  42.  These  may 
be  finished  and  replaced,  then  the  mold  closed. 


L_ 

Wv 

Wi^ 

::•:'•'-.'••:. 

:•:  V.-;  ^ 

1 

•  Jj^j^^ 

l^^^^l                                             5§l^§§ 

>;•'*"  y 

FIG.  41. 

A  pouring  basin  should  be  built  to  allow  pouring  from 
the  outside  of  the  flask.  The  riser  should  be  built  to 
the  height  of  the  basin  to  avoid  overflowing  onto  the 
flask. 

The  methods  above  given  may  be  used  for  many  forms 
of  pulleys  and  sheave-wheels.  Double-arm  pulleys  may 
be  made  in  this  manner  by  using  a  second  anchor  to  lift 
the  cheek  from  the  lower  set  of  arms.  The  thickness  of 
the  rim  may  be  increased  by  placing  thin  strips  inside 
of  the  ring.  In  pulleys  having  wide  face  it  is  best  to 
anchor  the  sand  in  the  outside  of  the  flask  so  that  it  may 
be  lifted  off.  The  face  of  the  pulley,  the  inside  of  the 


GREEN  SAND  MOLDING 


43 


rim,  and  the  bottom  of  the  rim  may  be  finished  easily 
when  thus  removed. 

For  making  sheave-wheels  by  use  of  the  pulley  ring 
the  grooves  are  made  in  core.     Sheaves  having  from  i  to 


fes*. 


'• 


V 


V 


N 


~1 


u 


_J 


FIG.  42. 

3  grooves  are  made  without  using  an  anchor  lift,  by 
coping  out  the  sand  above  the  arms  by  a  cope  lift. 
In  making  a  sheave,  the  method  of  procedure  is  the 
same  as  that  of  a  pulley  until  the  cope  is  lifted  off.  The 


44  FOUNDRY  PRACTICE 

sand  on  the  outside  of  the  pulley  ring  is  then  removed 
to  a  depth  equal  to  the  width  of  the  cores  which  form 
the  grooves.  The  centre  part  is  finished  as  in  the  case 
of  the  pulleys.  The  cores  are  set  about  the  cheek  by 
use  of  strips  which  are  the  thickness  of  the  metal  below 
the  grooves.  The  sand  is  filled  in  back  of  the  cores,  thus 
forming  the  outer  face  for  the  desired  sheave.  The 
strips  are  drawn  out  and  the  mold  prepared  for  closing. 

Columns  are  cast  with  centre  cores  of  such  a  size  that 
the  thickness  of  metal  on  the  outside  is  that  desired. 
Fig.  43  shows  a  column  that  is  here  taken  to  explain 
some  of  the  methods  for  making  such  forms  of  castings. 

The  pattern  used  is  shown  in  Fig.  44.  It  is  a  halved 
pattern  longer  than  the  desired  casting  and  having  the 
brackets  loose.  The  drag  is  rammed  in  the  customary 
manner.  Facing  is  used  all  over  the  pattern  when  the 
length  and  thickness  of  metal  will  allow  without  cold- 
shotting  the  end  away  from  the  gate.  The  ramming  must 
be  even  throughout  its  length,  and  is  best  made  much 
harder  than  on  smaller  castings.  The  parting  is  made 
and  the  other  half  of  the  pattern  is  placed  in  position. 
Facing  should  be  put  on,  the  same  as  in  the  drag.  It 
should  be  tucked  beside  the  pattern  to  allow  the  gaggers 
to  be  placed  near  the  pattern.  The  cope  is  then  placed 
on  and  an  upset  placed  over  the  brackets  to  give  sufficient 
depth  of  sand  above  the  pattern.  The  gaggers  are  set  in 
the  cope.  They  should  be  long  enough  to  reach  nearly  to 
the  top  of  the  flask  and  have  a  heel  about  6  in.  long.  The 
gaggers  will  be  most  effective  when  placed  in  the  division 
having  the  heel  extending  parallel  to  the  pattern  and  as 
close  as  possible  to  the  pattern.  When  pointed  toward 


GREEN  SAND  MOLDING 

a  * 


45 


o  x x  o 

o 

O -      o 

FIG.  43. 


FIG.  44- 


46  FOUNDRY  PRACTICE 

the  pattern  the  edge  is  liable  to  break  between  the  gaggers. 
It  is  only  necessary  to  ram  the  cope  one  bar  back  of  the 
collar.  The  gate  is  placed  in  this  division  and  above  the 
pattern.  A  riser  should  be  placed  above  the  large  bracket. 
When  the  column  has  metal  so  thin  that  the  iron  is  liable 
to  be  too  cold  when  it  reaches  the  bracket,  it  is  preferable 
to  have  a  gate  at  that  end  and  pour  with  a  bull  ladle,  thus 
supplying  hot  iron  for  the  brackets.  The  cope  should  be 
rammed  to  an  even  hardness  the  same  as  that  of  the  drag 
and  should  be  well  vented.  The  bracket  must  be  anchored 
as  strongly  as  possible,  having  a  gagger  come  between 
the  bracket  and  the  beam  connection  to  prevent  the 
metal  from  breaking  through.  The  ramming  around  the 
bracket  should  be  lighter  than  on  the  main  body  of  the 
pattern.  The  pressure  of  the  metal  is  not  sufficient  to 
prevent  scabbing  or  blowing  as  in  the  other  parts.  The 
pattern  should  be  held  firmly  to  the  cope  by  wood  screws 
while  the  cope  is  being  lifted  off. 

In  finishing  the  drag,  it  should  first  be  vented  by  run- 
ning the  wire  under  the  pattern  from  the  sides  of  the  flask 
and  leading  these  vents  off  at  the  parting.  Nails  should 
be  put  in  the  corners  near  the  collars  and  the  brackets. 
The  joint  may  be  wet  with  the  swab,  then  the  pattern 
drawn.  The  brackets  still  remain  in  the  drag.  A  large 
nail  should  be  placed  in  each  corner  of  the  bracket  and 
two  placed  between  the  bracket  and  beam  connection  to 
prevent  breaking  through,  as  the  metal  fills  one  before 
entering  the  other.  The  brackets  are  drawn  and  the  mold 
slicked.  The  cores  shown  at  B,  Fig.  45,  are  set  in  the 
collars  and  those  at  A  are  placed  in  the  beam  connections. 
These  cores  must  be  anchored  to  prevent  lifting,  due  to  the 


GREEN  SAND  MOLDING  47 

buoyancy  of  the  metal.  These  cores  may  be  held  by  nails 
so  placed  as  to  resist  an  upward  pressure.  The  end  stop- 
off  core  shown  at  C  is  placed  at  the  outer  edge  of  the  collars. 
This  core  is  the  same  thickness  as  the  metal  of  the  desired 
column.  The  chaplets  are  set  in  the  drag.  The  number 
of  chaplets  depends  upon  the  weight  and  length  of  the 
centre  core.  The  centre  core  is  placed  in  position  and  the 
end  stop-off  cores  are  placed  on  the  top  side.  These  small 
cores  should  be  fastened  so  that  they  will  not  be  pressed 
forward  while  ramming  up  the  ends  or  be  washed  in  by  the 
iron.  The  gate  comes  through  the  end  stop-off,  hence  it 


must  be  cut  away  back  to  where  the  metal  enters  from  the 
cope  and  of  a  width  to  give  the  desired  area  of  gate. 

The  cope  should  be  finished  similarly  to  the  drag  and 
the  small  cores  set  in  the  collars  and  the  beam  connection. 
The  edges  should  be  more  firmly  anchored  than  in  the 
drag,  so  as  to  ensure  holding  when  the  flask  is  closed. 

The  cope  chaplets  are  set  and  the  flask  may  be  closed. 

In  this  form  there  is  nothing  to  hold  the  metal  from 
forcing  the  end  cores  out,  hence  there  should  be  a  division 
of  the  flask  which  may  now  be  rammed  with  sand.  The 
vents  for  the  centre  cores  must  be  led  off  through  the  por- 
tion thus  rammed. 


48  FOUNDRY  PRACTICE 

The  pouring  basin  may  be  built  and  the  riser  raised  to 
the  level  with  it.  The  flask  is  clamped  and  chaplets  prop- 
erly wedged,  thus  it  is  ready  to  receive  the  metal. 

The  strength  of  facing  and  the  amount  which  may  be 
used  is  entirely  dependent  upon  the  thickness  of  the  metal 
and  the  length  of  the  column.  Generally,  when  the  metal 
is  i  in.  in  thickness,  facing  of  a  strength  of  from  i-io  to 
i- 1 6  should  be  used  all  over  the  pattern.  Small  columns 
up  to  9  in.  in  diameter  having  metal  less  than  i  in.  in  thick- 
ness should  not  be  covered  all  over  with  facing  except 
when  short. 

A  column  of  p-in.  diameter  and  f-in.  metal,  18  ft.  long 
may  be  made  with  facing  1-16  covering  one-half  its 
length.  With  facing  stronger  or  covering  more  of  the  pat- 
tern, the  iron  is  so  cold  before  reaching  the  opposite  end 
that  it  causes  cold-shots,  or  it  will  not  run  full. 

The  manner  of  gating  a  column  is  dependent  upon  the 
size  of  the  column.  For  small  and  thin  columns,  a  single 
gate  at  the  end  supplies  the  metal  fast  enough  and  enables 
forcing  in  case  the  metal  is  somewhat  cold.  In  larger 
sizes,  as  from  10  in.  up,  or  9  in.  having  thick  metal,  a  gate 
on  each  side  is  more  desirable.  The  metal  may  be  led  in 
by  the  end  core  or  at  the  side  by  a  runner  and  several  gates. 

In  making  cast  gears,  it  is  very  important  to  maintain 
the  exact  form  of  the  pattern  and  form  all  the  teeth  per- 
fectly. The  teeth  are  the  most  important  part  of  such  a 
casting,  for  if  some  are  out  of  shape  it  will  not  run  with  the 
gear  meshing  into  it,  hence  the  casting  cannot  be  used. 

The  sand  must  be  rammed  into  the  teeth  uniformly,  and 
that  as  soft  as  will  resist  the  pressure  of  the  metal.  In 
small  gears  it  can  be  done  best  by  riddling  the  sand  out- 


GREEN  SAND  MOLDING  49 

side  and  throwing  it  into  the  teeth  until  all  are  covered, 
then  ramming  up  the  backing  moderately  hard.  In  large 
gears  the  sand  should  be  nailed  or  rodded  while  being 
rammed  and  care  should  be  used  to  ram  the  teeth  to  an 
even  hardness. 

When  a  gear  is  so  small  that  facing  cannot  be  used,  mix 
new  sand  with  the  old  in  a  proportion  of  i  part  new  sand  to 
3  parts  old  sand  and  use  it  for  the  facing.  In  all  other 
gears  use  facing  varying  in  strength  according  to  size. 
Generally  use  facing  of  strength  of  i  part  sea  coal  to  12 
parts  sand.  Never  use  plumbago  or  blacking  on  the  teeth 
unless  they  are  of  large  enough  size  to  smooth  it  on  with  a 
brush  or  slick.  The  loose  dust  only  roughens  the  casting 
and  causes  a  dirty,  uneven  surface. 

The  teeth  of  a  gear  cannot  be  patched  with  tools  as  can 
corners  and  surfaces  of  a  common  mold.  The  form  of  the 
tooth  must  be  true,  hence  it  is  important  that  the  pattern 
draw  out  well,  leaving  the  teeth  without  tearing.  Some 
patterns  have  the  teeth  dovetailed  into  the  body,  then  if 
any  tooth  does  not  leave  the  mold  well  it  may  be  pressed 
down  and  drawn  out  separately.  With  other  patterns,  in 
case  of  patching  being  necessary,  the  pattern  must  be  re- 
placed and  the  tooth  re-formed. 

The  gate  must  always  be  placed  upon  the  centre  of  a 
gear,  as  the  teeth  would  be  very  liable  to  wash  if  the  metal 
entered  the  mold  from  the  rim. 

The  method  of  procedure  in  making  a  gear  from  a  solid 
pattern  may  be  shown  in  making  a  mold  for  the  bevel  gear 
shown  in  Fig.  46.  The  parting  comes  at  the  top  or  outer 
diameter  of  the  teeth  and  at  the  bottom  of  the  hub  at  the 
short  side  of  the  arms.  If  a  special  follow-board  or  match 


FOUNDRY  PRACTICE 


is  made  for  the  pattern,  the  drag  may  be  placed  and 
rammed.  In  other  cases,  a  match  must  be  made  on  the 
cope.  The  cope  is  laid  on  a  sand  bed  with  the  pins  up- 
ward. Sand  is  filled  in  and  rammed  to  a  height  that 
brings  the  parting  line  of  the  teeth  even  with  that  of  the 
flask  when  the  pattern  is  in  position.  The  sand  is  rammed 
around  the  pattern  until  the  level  of  the  parting  is  reached. 
The  parting  between  the  arms  is  more  easily  made  from 
this  side  than  after  the  pattern  is  reversed;  so  this  portion 


FIG.  46. 

of  the  parting  is  made  and  parting  sand  put  upon  it.  The 
drag  is  placed  upon  the  cope,  facing  sand  is  thrown  into  the 
teeth  until  they  are  well  covered,  sand  is  riddled  over  this, 
and  the  remainder  is  filled  and  rammed.  The  drag  is 
vented,  care  being  used  not  to  strike  the  teeth  of  the  pat- 
tern. The  whole  is  turned  over  and  the  cope  lifted  while 
the  pattern  is  held  into  the  drag.  The  parting  at  the  out- 
side of  the  pattern  is  first  made  and  the  sand  removed  from 
the  centre  down  to  the  pattern.  The  pattern  and  ad- 
jacent sand  are  marked  at  some  point  by  which  to  replace 


GREEN    SAND   MOLDING  51 

the  pattern  after  it  has  been  removed.  The  pattern  is 
rapped  to  loosen  the  sand  in  the  teeth,  then  drawn,  carry- 
ing with  it  the  sand  above  the  parting  previously  made. 
The  pattern  is  brushed  clean  and  replaced,  which  com- 
pletes the  parting  of  the  drag.  Facing  is  riddled  over  the 
face  of  the  drag  and  the  cope  is  replaced.  Soldiers  are 
placed  to  anchor  the  sand  between  the  arms.  These 
should  extend  to  the  top  of  the  cope  to  ensure  sufficient 
strength  to  hold  the  sand  firmly  when  the  pattern  has  been 
removed.  The  gate  stick  is  placed  on  the  hub  beside  the 
core  print.  Facing  is  filled  in  to  cover  the  pattern  and 
rammed  between  the  arms  with  a  hand  rammer  or  rod  that 
will  tighten  the  sand  evenly  around  the  soldiers.  The  re- 
mainder of  the  cope  is  filled  and  rammed,  care  being  used 
to  ram  around  the  soldiers  without  striking  them.  The 
cope  is  well  vented  and  the  gate  stick  removed  without 
reaming  or  enlarging  the  hole,  so  that  it  may  be  replaced 
after  the  flask  is  closed.  A  wood  screw  or  draw-spike  is 
placed  in  the  hub  through  the  gate.  This  is  held  and 
slightly  rapped  as  the  cope  is  lifted  off.  The  rapping  frees 
the  teeth  and  the  pattern  is  held  firmly  in  the  cope  by  lift- 
ing on  the  screw.  The  sand  around  the  pattern  and  be- 
tween the  arms  is  patched  and  nailed  where  necessary.  In 
large  patterns  the  sand  should  be  nailed  before  drawing 
the  pattern,  to  prevent  the  sand  from  loosening  or  drop- 
ping while  closing  the  mold.  The  sand  at  the  edges  of  the 
pattern  is  moistened  with  the  swab  and  the  pattern  drawn. 
In  case  any  of  the  teeth  were  torn  or  damaged  when  the 
cope  was  lifted,  the  pattern  should  be  replaced  on  the  drag 
and  the  tooth  re-formed  by  ramming  in  sand  with  a  small 
rod  or  nail.  The  pattern,  then  drawn,  should  give  a  per- 


52  FOUNDRY  PRACTICE 

feet  set  of  teeth  as  desired.  Blacking  may  be  put  upon  the 
cope  and  slicked,  but  it  is  preferable  to  leave  the  drag  with- 
out blackening.  The  centre  core  is  vented  off  at  the 
bottom  and  has  its  top  vent  closed  with  sand  so  the  iron 
cannot  flow  into  it.  The  flask  is  closed  and  the  gate  stick 
replaced.  A  basin  is  built  about  it,  as  shown  in  Fig.  35, 
so  that  the  metal  will  not  be  poured  directly  into  the  gate, 
giving  the  additional  strain  due  to  the  metal  dropping  from 
the  ladle. 


CHAPTER  H 

DRY  SAND  MOLDING 

Dry  sand  molds  are  made  similarly  to  green  sand 
mold,  using  special  facings.  The  mold  is  blackened  with 
a  wet  blacking  and  slicked  smooth,  then  dried  in  an  oven 
or  by  special  drying  apparatus.  The  surface  after  drying 
is  hard,  similar  to  a  brick.  This  gives  a  surface  that  can 
withstand  great  pressures  where  a  high  head  is  necessary 
in  casting.  The  dry  face  coated  with  the  blacking  pre- 
vents fusion  of  the  sand  and  thus  gives  a  smooth  casting. 
Hence  where  it  is  desirable  to  have  a  smooth  casting,  or 
when  the  head  pressure  is  great;  dry  sand  or  loam  molds 
are  used. 

The  mixture  used  next  to  the  pattern  in  dry  sand  work 
is  called  the  dry  sand  facing.  That  used  to  fill  in  between 
the  facing  and  the  flask  is  called  the  backing  sand.  Old 
molding  sand  forms  a  good  backing.  Dry  sand  facing 
comprises  a  mixture  which  will  become  hard  and  strong 
when  dried  and  still  be  open  to  allow  free  escape  of  the 
gases.  The  mixture  for  the  dry  sand  facing  is  dependent 
upon  the  sand  obtainable  in  the  locality.  A  sand  too 
strong  with  clay  gives  the  hard,  strong  face  to  the  mold  but 
will  not  allow  the  gases  to  escape.  Where  the  molding 
sand  is  of  a  fine  quality  and  quite  strong  with  clay,  Re- 
ceipts Nos.  i  and  2  will  make  a  good  facing.  The  propor- 

53 


54  FOUNDRY  PRACTICE 

tion  of  sharp  or  lake  sand  may  be  varied  where  the  facing 

is  found  to  be  too  close  or  too  open. 

Receipt  No.  i.     Mix  i  part  new  molding  sand,  i  part  old 

molding  sand,  and  2  parts  sharp  or  core  sand.     To  30 

parts  of  sand  add  i  part  flour  and  i  part  sea  coal.     Wet 

with  water. 
Receipt  No.  2.     Mix  4  parts  of  molding  sand  with  i  part 

sharp  or  lake  sand.     To  30  parts  of  sand  add  i  part  of 

flour.     Wet  with  clay  wash. 
Receipt  No.  3.     Mix  i  part  of  molding  sand  with  i  part  of 

bank  sand.    To  30  parts  of  sand  add  ij  parts  of  sea 

coal  and  i  part  of  flour.     Wet  with  clay  wash. 

Dry  sand  may  be  rammed  much  harder  than  green  sand. 
The  facings  are  more  open  and  the  moisture  is  evaporated 
from  it  before  casting.  The  ramming  should  be  even, 
because  unevenness  may  cause  trouble  similar  to  green 
sand  though  not  so  readily.  Hard  spots  in  the  face  of  a 
dry  sand  mold  will  cause  a  scab  on  the  casting. 

The  importance  of  venting  dry  sand  must  not  be  under- 
estimated. After  the  mold  is  dried  there  is  no  moisture  to 
form  steam,  as  in  the  green  sand  mold.  The  other  gases 
are  still  formed  at  the  face  of  the  casting  and  must  be  car- 
ried away  or  the  casting  is  liable  to  blow  or  scab.  When 
there  is  six  inches,  or  more,  of  sand  between  the  casting 
and  the  flask  no  venting  is  necessary.  When  less  than 
six  inches  there  is  not  sufficient  space  to  relieve  the 
pressure  unless  there  are  holes  in  the  flask  for  release  or 
vents  for  carrying  off  the  gases. 

As  the  body  of  sand  increases,  the  pressure  of  the  gases 
decreases,  hence  the  smaller  the  body  of  sand  the  greater 
the  necessity  of  vents.  Large  bodies  of  sand  give  relief  to 


DRY  SAND  MOLDING  55 

the  pressure  through  its  openings  or  porosity.  It  literally 
holds  the  gases  without  increasing  the  pressure  to  a  danger- 
ous degree.  Pockets,  corners,  flanges,  and  similar  projec- 
tions require  venting  and  provision  for  conducting  off  the 
gases,  but  not  so  extensive  as  in  green  sand  molds. 

In  green  sand,  when  the  joint  comes  together  closely,  it 
may  compress  slightly  without  damage  when  the  flask  is 
clamped.  In  dry  sand,  the  hard  surface  will  not  admit  of 
any  compression  without  breaking  away.  This  is  avoided 
by  cutting  away  the  joint  slightly  at  the  edge  of  the  pattern 
before  or  after  drawing.  This  leaves  a  fin  on  the  casting 
which  may  be  chipped  off.  The  edges  where  cores  bear 
should  be  similarly  treated.  This  fin  should  be  from  J  in. 
to  J  in.^  in  thickness  and  should  slope  back  about  3  in. 
The  maxim  "  It  is  better  to  have  a  fin  than  a  crush  "  should 
be  remembered  in  dry  sand  work. 

The  finishing  of  dry  sand  molds  gives  the  face  which 
causes  the  casting  to  peel.  After  the  pattern  is  removed 
the  face  of  the  mold  is  dampened  with  molasses  water  or 
beer  wash.  This  makes  the  facing  stick  together  firmly 
and  gives  a  smooth  compact  surface  when  slicked.  The 
flour  in  the  facing  makes  it  rather  pasty  so  it  can  be  shaped 
more  easily  than  a  green  sand  mold.  The  entire  face  is 
slicked  with  the  tools  before  blackening.  Any  part  torn  by 
the  pattern  may  be  patched  similarly  to  a  green  sand  mold. 
The  face  of  the  mold  may  be  slicked  much  harder  than  in  a 
green  sand  mold.  The  sand  is  much  more  open  and  held 
together  by  the  flour  so  it  will  not  scab  so  easily  as  green 
sand. 

The  blacking  is  put  upon  the  dry  sand  mold  to  close  the 
pores  of  the  sand  and  give  a  smooth  surface  that  will  peel 


56  FOUNDRY  PRACTICE 

from  the  casting.  The  mixtures  given  below  have  yielded 
very  good  results.  The  proportions  may  be  varied  to  suit 
the  qualities  of  the  ingredients  and  to  give  better  results  in 
particular  cases.  When  the  blacking  cracks  or  peels  upon 
drying,  the  body  has  been  put  on  too  heavy  or  there  is  too 
great  a  percentage  of  clay  wash. 

Receipt  No.  i  is  used  for  light  castings  or  where  the 
thickness  of  metal  is  less  than  two  inches.  Receipt  No.  2 
is  better  for  heavy  or  thick  castings.  Receipt  No.  3  is  a 
very  simple  mixture  which  gives  good  results  on  small  or 
thin  castings. 

Receipt  No.  i. — Mix  i  part  charcoal  blacking,  i  part 
Lehigh  blacking,  2  parts  plumbago.  Wet  with  molasses 
water  or  sour  beer. 

Receipt  No.  2. — Mix  8  parts  charcoal  blacking,  8  parts 
plumbago,  i  part  thick  clay  wash.     Wet  with  sour  beer 
and  allow  to  stand  2  or  3  days  before  using. 
Receipt  No.  3. — Mix  a  clay  wash  from  red  clay  of  a  thick- 
ness that  will  color  the  hand  when  dipped  into  it.     Add 
plumbago  until  it  becomes  of  the  thickness  desired. 
The  molds  are  dried  by  heating  sufficiently  to  drive  off 
the  water  from  the  sand.     This  is  accomplished  in  many 
different  ways  to  suit  the  conditions.     The  best  method  is 
to  dry  the  mold  in  an  oven.     The  oven  for  this  purpose  is 
similar  to  the  core  ovens  which  admit  a  core  car.     The 
molds  are  put  on  the  car  for  placing  in  the  oven.     The 
temperature  is  kept  between  500°  and  600°  F.     This  will 
not  burn  the  face  of  the  mold  and  dries  it  very  rapidly. 

Some  molds  are  dried  by  injecting  hot  air.  The  mold 
is  closed  with  the  pipe  from  a  heater  projecting  into  it. 
All  the  openings  and  the  parting  are  sealed  with  clay  to 


DRY  SAND  MOLDING  57 

resist  the  air  pressure.  The  air  is  kept  under  a  small  pres- 
sure which  forces  it  out  through  the  sand  and  vents.  The 
heat  dries  the  sand,  giving  the  desired  result.  One  form 
of  apparatus  to  accomplish  this  would  consist  of  a  heater 
or  large  stove  having  a  coil  of  pipe  in  the  place  of  the  lining. 
The  air  is  forced  through  this  by  a  root  blower.  The 
blower  is  driven  by  a  motor  or  belted  from  a  shaft.  The 
coil  in  the  heater  is  connected  to  the  mold  by  a  pipe.  The 
heater  should  be  as  close  to  the  mold  as  convenient  to  re- 
duce the  cooling  of  the  air  before  reaching  the  mold. 

Another  common  method  of  drying  is  to  use  the  fire 
pot.  A  charcoal  fire  is  built  in  a  fire  pot  and  lowered  into 
the  mold.  It  should  be  kept  at  equal  distances  on  all 
sides  from  the  faces  to  be  dried.  The  fire  pot  should  con- 
form to  the  general  shape  of  the  mold.  This  gives  un- 
equal drying  on  an  irregular-shaped  mold.  When  care- 
fully followed  very  satisfactory  results  are  obtained. 

The  face  of  the  parting  was  slicked  down  before  drying, 
so  that  the  sand  does  not  touch  when  the  flask  is  closed. 
It  is  therefore  necessary  to  place  upon  the  face  of  the  part- 
ing something  that  will  seal  this  opening  and  hold  the 
metal.  A  stiff  dough  made  of  flour  and  water,  then  rolled 
out  into  long  strings,  serves  the  purpose.  The  dough  will 
flatten  without  damage  to  the  mold,  when  the  two  parts  of 
the  mold  come  very  near  together.  These  strings,  often 
called  noodles,  are  placed  around  the  edge  of  the  mold  and 
over  cores  which  should  bear  on  the  cope. 

Dry  sand  may  be  employed  without  the  use  of  facing. 
It  is  claimed  by  many  of  the  best  foundrymen  that  it  is 
unnecessary  to  use  flour  and  sea  coal  in  the  facing  for  a 
dry  sand  mold  where  a  good  blacking  is  used.  The  object 


58  FOUNDRY  PRACTICE 

of  the  flour  is  to  make  the  face  hard  when  dry,  as  a  core. 
The  sea  coal  is  to  prevent  fusion  of  the  sand  and  to  peel 
the  casting.  For  the  medium-sizedca  sting  in  dry  sand, 
the  facing  used  is  i  part  new  molding  sand  with  i  part  old 
molding  sand  wet  with  clay  wash  and  riddled  through  a 
No.  6  riddle.  The  backing  may  be  of  the  coarsest  heap 
sand.  The  blacking  for  the  mold  is  made  from  Receipt 
No.  3.  Castings  made  by  this  method  have  been  found  to 
peel  and  to  leave  as  smooth  and  bright  a  surface  as  any  dry 
sand  mold. 

In  many  cases  where  previously  dry  sand  molds  were 
used,  it  is  found  as  satisfatory  to  only  skin-dry  the  mold. 
The  mold  is  handled  in  the  same  manner  as  a  dry  sand 
mold,  but  the  drying  is  continued  only  long  enough  to  dry 
the  sand  for  a  depth  of  about  two  inches. 

Some  kinds  of  sand  which  are  quite  strong  with  clay  do 
not  require  the  flour  used  in  the  dry  sand  facing,  but  hold 
well  when  moistened  with  clay  wash,  molasses  water,  or 
beer  wash.  Generally  the  same  facing  is  used  as  in  dry 
sand  molds. 

A  skin-dried  mold  has  the  hard  surface  but  the  backing 
is  still  soft.  This  increases  the  danger  of  crushing  when 
closed  and  of  the  cutting  of  the  metal  when  poured.  The 
mold  should  be  cut  away  at  the  parting  and  the  entire 
joint  slicked  down  slightly  to  ensure  the  bearing  on  the 
flask  instead  of  on  the  sand.  The  dried  crust  will  separate 
from  the  green  backing  much  more  easily  than  a  dried 
mold  would  break.  When  a  casting  is  so  gated  that  it 
would  be  liable  to  cut  if  the  sand  were  green,  it  should  be 
well  nailed  in  front  of  the  gate  before  skin-drying. 

The  face  of  the  mold  is  finished,  blackened,  and  slicked 


DRY  SAND  MOLDING  59 

the  same  as  in  dry  sand.  The  blacking  may  be  put  on 
dry,  then  moistened  with  molasses  water;  or,  better,  the 
wet  blacking  mixture  may  be  used. 

A  mold  is  skin-dried  by  the  same  method  used  for  dry 
sand  molds.  For  slightly  drying  the  face  of  small  molds, 
gasoline  may  be  sprayed  on  the  surface  and  burned  off,^ 
giving  a  hard  face.  This  may  be  used  with  some  kinds  of 
sand  in  the  common  green  sand  mold,  giving  the  casting 
the  appearance  of  coming  from  a  dry  sand  mold.  It  gives 
a  smoother  casting  in  small  work  than  the  wet  face. 

Many  castings  cannot  be  easily  made  in  a  flask,  owing 
to  their  size  or  form.  These  are  made  into  the  floor  with 
a  cope  to  cover  a  part  or  the  whole.  This  division  of 
molding  is  called  pit  molding.  Fly  wheels,  large  sheaves, 
and  large  gears  are  made  in  this  way  more  easily  than  in 
the  drag  of  a  flask.  Many  large  castings  that  might  other- 
wise be  made  in  a  flask  are  bedded  into  the  pit  when  there 
is  no  flask  at  hand.  It  is  much  cheaper  to  bed  the  pattern 
into  the  floor  than  it  would  be  to  make  a  flask  when  only 
one  casting  is  desired.  Some  molds  are  subjected  to  an 
intense  down  and  side  pressure  when  the  metal  is  poured. 
It  would  require  a  very  strong  flask  to  withstand  this  stress, 
hence  it  would  be  very  expensive.  If  placed  in  the  pit,  the 
sand  is  rammed  hard  to  the  adjoining  ground,  hence  the 
pressure  is  resisted  except  that  on  the  cope,  which  must  be 
provided  for  by  weights,  or  the  cope  must  be  bolted  to 
anchors  in  the  ground. 

Since  there  is  no  opening  at  the  bottom,  as  in  the  case  of 
a  flask,  for  the  escape  of  the  gases,  provision  must  be  made 
to  carry  these  off  from  the  bottom  of  the  mold.  Below  the 
mold  at  a  depth  of  about  2  ft.,  a  layer  of  coke  or  cinders  is 


60  FOUNDRY  PRACTICE 

placed  to  collect  the  gases.  This  coke  bed  is  connected 
to  the  surface  by  a  vent  pipe.  All  the  vents  from  the  lower 
portion  of  the  mold  extend  through  to  this  coke  bed,  which 
gives  relief  to  the  gases. 

To  make  the  coke  bed  the  pit  is  dug  out  about  i  £  or  2  ft. 
deeper  than  the  mold  would  require.  It  is  then  leveled  off 
and  a  layer  of  coke  of  about  the  size  of  an  egg  is  put  in  to 
a  thickness  of  4  or  8  in.  The  coke  is  covered  with  hay, 
straw,  or  burlap  to  keep  the  sand  from  packing  solid 
around  the  coke.  A  pipe  of  ample  size  to  give  free  vent 
to  the  bed  is  placed  at  the  outside  to  connect  with  the  sur- 
face. The  lower  end  of  the  pipe  rests  on  the  coke  and  is 
so  covered  with  coke  that  the  sand  cannot  enter  the  pipe. 
The  sand  may  now  be  filled  in  to  form  the  mold  above. 

Making  castings  by  use  of  sweeps,  in  the  place  of  pat- 
terns, is  being  extensively  practiced  where  but  a  single 
casting  is  required.  The  time  required  for  making  such 
a  mold  is  greater  than  that  required  where  a  pattern  is 
used,  but  the  expense  of  making  the  pattern  is  saved,  ex- 
cept for  forming  the  sweeps,  which  is  very  slight. 

A  simple  form  of  the  necessary  rigging  is  illustrated  in 
Fig.  47.  The  socket  A  is  a  cast  base  having  a  tapered  hole 
in  the  centre  for  holding  the  spindle.  The  spindle  B  is 
made  of  steel  or  cast  iron,  and  is  uniform  in  diameter, 
having  its  lower  end  tapered  to  fit  the  socket.  A  collar  is 
fitted  to  the  spindle  and  has  a  set  screw  for  fastening  it  at 
any  point.  This  carries  the  sweep  arm  at  the  desired 
height.  The  revolving  arm  D  is  made  of  cast  iron,  bored 
-to  fit  the  spindle  and  having  slots  for  bolting  the  sweep  and 
allowing  adjustment.  The  sweep  is  made  of  wood  having 
the  special  shape  for  the  desired  casting. 


DRY  SAND  MOLDING 


6l 


The  process  of  forming  a  green  sand  mold  by  use  of  a 
sweep  may  be  noted  in  making  a  cover,  as  shown  in  Fig. 
48.  A  hole  is  dug  into  the  floor  and  the  socket  is  bedded 
in  so  as  to  hold  the  spindle  plumb.  A  coke  bed  is  formed 
around  it  with  the  vent  pipes  leading  to  the  surface.  Sand 


0 

0 

0 

0 

0 

o 

o 
o 

0 
0 

0 
0 

0 

0 

0 
0 

1  1 

FIG.  47. 

is  filled  in  and  rammed  to  a  level  shown  by  line  MN,  Fig. 
49.  This  is  well  vented  to  the  coke  bed  with  a  f  in.  wire. 
Facing  sand  is  filled  in  and  rammed  to  the  height  that  it  is 
to  be  struck  off  and  to  approximately  conform  to  the  line 
ACB  of  the  top  of  the  cover.  The  sweep  arm  is  placed 
upon  the  spindle  above  the  collar  C.  The  sweep  is  made 


62 


FOUNDRY  PRACTICE 


to  conform  exactly  to  the  upper  face  of  the  cover.     It  is 
fastened  to  the  arm  so  as  to  have  the  outer  end  at  A  strike 


FIG.  48. 





mm 


FIG.  49. 

a  level  face,  which  gives  the  guide  for  the  location  of  the 
sweep  to  be  used  later.  The  collar  is  adjusted  to  give  the 
outer  edge  of  the  cover  at  the  floor  line.  The  surface  ACB 


DRY  SAND  MOLDING  63 

is  swept  by  revolving  the  sweep  away  from  the  cutting 
edge,  as  indicated  at  H. 

The  sweep  and  collar  are  removed  and  the  surface 
slicked  for  a  parting  surface  as  usual.  Parting  sand  is 
then  put  upon  the  surface  and  a  cope  placed  in  position 
and  staked  at  the  corners  to  allow  replacing  after  removing 
for  finishing  the  mold.  A  short  pipe  or  box  is  placed 
around  the  spindle  to  allow  lifting  the  cope,  as  at  P,  Fig. 
49.  The  cope  is  rammed  as  usual  with  the  necessary 
gates  and  risers.  The  cope  is  lifted  off,  finished  and 


blackened.  The  pipe  at  the  centre  is  drawn  back  and 
filled,  then  faced  to  the  desired  surface  of  the  cope,  care 
being  used  to  properly  vent  it.  A  second  sweep,  E,  Fig. 
50,  is  placed  upon  the  spindle  which  exactly  conforms  to 
the  under  side  of  the  cover,  having  the  edge  A  as  a  gauge 
for  the  depth  and  following  the  level  surface  previously 
swept.  The  collar  on  the  spindle  is  adjusted  so  that  the 
level  face  of  the  sweep  just  touches  the  level  face  previously 
swept,  then  the  drag  is  swept  out  to  the  desired  shape. 
The  sweep  and  spindle  are  now  removed  and  the  face  of 
the  mold  finished.  The  opening  left  by  the  spindle  is 
filled  with  cinders  nearly  to  the  surface,  then  facing  sand  is 


64  FOUNDRY  PRACTICE 

rammed  in  until  the  desired  face  is  reached.  The  drag  is 
finished  and  blackened,  with  the  gates  and  risers  properly 
connected  to  the  mold.  The  cope  may  be  replaced  by  aid 
of  the  stakes,  which  completes  the  mold  as  shown  in  Fig. 

Methods  of  casting  fly  wheels  are  various.  Fly  wheels 
are  made  from  part  patterns  which  are  moved  about  a 
centre  spindle.  The  arms  are  made  in  core,  while  the  rim 
may  be  in  green  sand,  core  sand  or  loam.  The  method  of 
procedure  in  making  a  mold  for  a  fly  wheel  will  be  given 


FIG.  51. 

in  a  general  way,  for  the  details  cannot  be  understood 
until  the  actual  experience  has  been  met  with. 

The  coke  bed  is  made  under  the  rim  to  extend  inside 
part  way.  The  socket  for  the  spindle  is  set  in  the  centre 
and  below  the  hub  cores.  This  socket  is  so  leveled  that 
the  spindle  stands  exactly  plumb. 

The  bottom  core  for  the  hub  is  located  about  the  spindle. 
A  sweep,  so  shaped  as  to  form  a  bed  for  the  arm  cores  of 
the  wheel,  is  then  placed  on  the  spindle.  This  sweep  has 
its  lower  edge  shaped  like  the  strike  stick  previously  men- 
tioned. 

The  bed  is  rammed  and  struck  off  with  the  sweep  over 


DRY  SAND  MOLDING  65 

the  entire  portion  within  the  rim  of  the  wheel.  This  gives 
a  bed  such  that  when  the  arm  cores  are  laid  upon  it  the 
centre  line  of  the  arm  is  level. 

The  arm  cores  are  so  placed  upon  the  bed  that  their 
outer  ends  just  touch  the  inner  face  of  the  pattern  for  the 
rim.  This  is  gauged  by  fastening  a  vertical  piece  onto  the 
sweep  previously  used  at  the  same  radius  as  the  inner  por- 
tion of  the  pattern.  The  collar  on  the  spindle  is  fastened 
so  as  to  support  the  sweep  above  the  cores.  The  cores 
are  placed  so  the  vertical  piece  on  the  sweep  will  just  clear 
the  end,  thus  giving  the  desired  radius. 

The  pattern  is  placed  upon  the  spindle  and  the  rim  is 
rammed,  a  section  at  a  time.  Each  time  the  pattern  is 
moved  it  is  kept  at  an  exact  level,  thus  when  the  last  sec- 
tion is  made  the  pattern  strikes  exactly  where  it  started. 
With  wheels  having  a  straight  rim  without  flanges,  both 
faces  may  be  rammed  in  green  sand.  Where  there  is  a 
flange  at  both  edges,  various  methods  are  used.  When 
the  rim  is  light  and  the  face  less  than  14  in.,  the  lower 
flange  may  be  made  by  cores  laid  while  ramming  the  mold, 
and  the  outer  face  rammed  at  the  same  time.  When 
large  it  is  preferable  to  make  the  outer  face  in  core  or  loam. 
The  pattern  then  has  a  core  print  below  the  face  and  one 
above  it  and  the  green  sand  is  rammed  only  on  the  inside 
of  the  rim.  The  cores  for  the  face  bear  on  the  green  sand 
above  and  below  the  casting  and  extend  to  the  inner  face 
of  the  flange.  These  cores  are  held  in  place  by  ramming 
the  sand  solid  back  of  the  cores,  bringing  the  floor  level 
with  the  top  of  the  core.  The  cores  may  also  be  held  by 
binding  plates  and  supports  to  hold  the  outward  pressure 
on  the  rim  when  the  mold  is  poured.  When  the  outer  face 


66  FOUNDRY  PRACTICE 

is  made  of  green  sand,  the  top  is  covered  with  cores,  then 
weighted  down  to  hold  the  pressure. 

The  gates  are  placed  on  the  hub  with  a  runner  and  pour- 
ing basin  leading  to  the  outside  of  the  rim,  where  it  is  acces- 
sible to  the  ladle.  Risers  are  placed  on  ilie  rim  and  the 
casting  fed  through  the  gates  and  the  risers,  when  the  rim 
is  heavy  enough  to  require  feeding. 

Loam  is  used  to  make  large  molds  of  the  same  type  as 
dry  sand.  Loam  can  be  easily  shaped  by  use  of  a  sweep, 
and  when  dried  will  resist  great  pressures  and  will  give  a 
casting  with  smooth  surface  the  same  as  dry  sand.  Loam 
is  chiefly  used  where  the  whole  or  a  part  is  made  with  a 
sweep. 

Loam  must  be  of  a  very  open  texture,  so  that  in  general 
the  mold  requires  but  little  venting.  Corners,  pockets, 
projections,  and  parts  not  having  free  relief  to  the  gases 
are  safer  when  vented  and  these  vents  led  to  the  outside. 
Hard-burned  brick  should  never  be  used  for  the  face  of  the 
mold,  as  it  prevents  the  escape  of  the  gases.  The  courses 
of  brick  are  occasionally  separated  by  a  layer  of  straw  to 
give  better  venting. 

The  body  portion  of  a  loam  mold  is  made  of  bricks. 
This  conforms  approximately  to  the  pattern  or  desired  face 
of  the  mold.  The  bricks  are  laid  up  in  courses  so  as  to 
break  joints  and  to  bind  the  whole  firmly  together.  They 
are  laid  in  a  coarse,  open  mixture  of  loam  to  aid  the  escape 
of  gases.  The  bricks  must  be  of  a  soft  porous  kind.  In 
some  cases  bricks  are  made  from  loam  for  forming  por- 
tions of  the  brick  wall.  These  are  more  porous  and  crush 
more  easily  than  common  bricks  when  the  casting  shrinks. 
They  are  made  from  a  stiff  mixture  of  coarse  loam  just 


DRY  SAND  MOLDING  67 

soft  enough  to  work  easily.  The  bricks  are  made  in  the 
box  and  laid  on  a  plate  whose  face  has  been  oiled,  and  are 
then  dried  in  the  oven. 

The  bricks  are  given  a  first  coat  of  coarse,  open  loam, 
swept  to  shape,  and  a  second  or  finishing  coat  of  loam 
which  is  finer  and  thinner.  The  thickness  should  never 
be  less  than  f  in.  to  f  in.  for  plane  surfaces,  and  not  less 
than  i  in.  in  pockets,  projections,  etc.  The  thickness  of 
the  metal  does  not  gauge  the  thickness  of  the  loam,  be- 
cause a  heavy  casting  will  scab  as  quickly  as  a  thin  one. 
The  thicker  the  loam,  the  better  the  venting. 

The  loam  mixture  is  more  of  a  mud  than  that  of  green 
or  dry  sand.  It  contains  much  clay  combined  with  sharp 
sand  and  other  materials  to  make  it  open.  The  exact 
mixture  is  entirely  dependent  upon  the  sand  used.  In  a 
few  places  the  natural  loam  is  found  which  may  be  used 
without  any  additions.  The  mixture  must  contain  enough 
clay  to  hold  the  sand  together.  If  the  mixture  is  too  weak 
with  clay,  it  will  crumble  when  compressed  in  the  hand. 
When  too  strong,  an  experienced  mechanic  can  tell  by  the 
feeling,  but  no  easy  method  can  be  pointed  out.  When 
the  mixture  is  too  weak  the  face  of  the  mold  will  crack  or 
crumble  easily.  When  too  strong  or  close  the  casting  will 
scab,  as  the  iron  will  not  lie  quiet  against  it.  The 
percentage  of  clay  determines  its  condition.  The  mix- 
ture giving  the  best  results  can  only  be  told  when  the 
sands  to  be  used  are  known.  Several  mixtures  are  given 
below  which  give  good  results  at  different  places,  using 
the  sands  available  at  the  particular  place.  These  may 
be  taken  as  general  guides  and  varied  to  suit  the  sands 
used.  The  clay  wash  generally  consists  of  6  to  8  parts 


68  FOUNDRY  PRACTICE 

of  clay  to   i  of  flour,  wet   with   water   to   the  desired 

consistency. 

Receipt  No.  i. — 4  parts  loam  sand,  i  or  2  parts  sharp 

sand,  i  part  dried  horse  manure.     Wet  with  medium 

thick  clay  wash. 
Receipt  No.  2.— 4  parts  molding  sand,  5  part   sharp  sand, 

ij  parts  dried  horse  manure,  J  part  dried  and  sifted  fire 

clay,  J  part  sea  coal.     Wet  with  fair  clay  wash. 
Receipt  No.  3. — 3  parts  fire  sand,  2  parts  molding  sand,  i 

to  10  parts  horse  manure.     Wet  with  thick  clay  wash. 
Receipt  No.  4. — 4  parts  fire  sand,  i  part  molding  sand,  i 

part  dry  riddled  fire  clay,  i  part  white  pine  sawdust. 

Wet  with  thin  clay  wash. 
Receipt  No.  5. — 2  parts  loam  sand,  2  parts  sharp  sand,  i 

part  old  burned  loam  sand,  i  part  horse  manure.    Wet 

with  thin  clay  wash. 


CHAPTER  III 

MOLDING    SAND,  MOLDERS'   TOOLS,  MACHINES,   AND 
EQUIPMENT 

A  sand  suitable  for  molding  must  be  open  to  allow  the 
escape  of  gases  and  must  be  able  to  hold  a  given  form  to 
withstand  pressure  and  wash  of  the  metal.  Such  a  sand 
has  a  percentage  of  clay,  or  binding  material,  which  will 
hold  the  mass  together  firmly  when  dampened  and  com- 
pressed. If  the  percentage  of  clay  becomes  too  great,  the 
sand  is  too  close  when  compressed,  so  the  gases  cannot 
pass  off;  then  the  metal  will  not  lie  quietly  against  the  face 
of  the  sand. 

The  molding  sands  used  in  different  parts  of  the  country 
vary  greatly  in  their  composition.  Those  high  in  clay 
must  be  used  with  as  little  water  as  possible  and  must  not 
be  compressed  or  rammed  much,  as  the  mold  must  give 
free  escape  for  gases  through  the  sand.  The  coarse  sands 
very  low  in  clay  may  require  much  water  and  hard  ram- 
ming in  order  to  form  a  satisfactory  mold.  The  tempering 
and  ramming  of  the  sand  must  be  largely  gauged  by  the 
nature  of  the  sand  the  molder  has  at  hand. 

Tempering  the  sand  means  the  mixing  and  wetting  of 
the  sand  ready  for  making  a  mold.  It  is  otherwise  known 
as  cutting  over  the  sand. 

69 


OP   THE 

UNIVERSITY 

«~>r 


70  FOUNDRY  PRACTICE 

The  sand  should  be  mixed  evenly  and  to  a  dampness 
such  that  it  will  stick  together  when  squeezed  in  the  hand, 
but  not  so  wet  as  to  show  moisture  or  dampen  the  hand. 
The  sand  pile  should  be  opened  out  so  that  there  will  be 
no  holes  in  which  the  water  will  accumulate.  The  water 
should  then  be  thrown  over  the  sand  in  thin  sheets  by 
swinging  the  pail  with  the  bottom  slightly  ahead  of  the  top. 
In  this  manner  the  water  is  distributed  evenly  and  does  not 
cause  mud  in  spots.  If  the  sand  is  wet  excessively  in 
spots,  as  by  throwing  the  water  on  the  pile  in  a  body,  it  re- 
quires much  more  shoveling  to  obtain  an  even  temper, 
hence  loss  of  time.  The  sand  should  then  be  shoveled 
over  in  order  to  mix  thoroughly.  The  shoveling  should 
be  done  so  as  to  scatter  the  sand  when  casting  it  from  the 
shovel.  This  is  accomplished  by  giving  the  handle  of  the 
shovel  a  twist  just  as  the  sand  is  leaving  it.  When  wishing 
to  throw  the  sand  to  a  distant  point,  it  should  be  allowed 
to  leave  the  shovel  in  a  solid  mass,  but  this  does  not  mix 
it  evenly.  In  mixing,  a  space  should  always  be  kept  be- 
tween the  pile  from  which  the  sand  is  taken  and  the  one 
to  which  it  is  thrown.  If  this  is  not  observed  some  of  the 
sand  will  not  be  thoroughly  mixed.  After  the  sand  has 
been  shoveled  over  once  it  is  seldom  found  to  be  mixed 
thoroughly,  which  makes  it  preferable  to  cut  it  over  from 
two  to  three  times.  All  the  water  necessary  for  the  proper 
tempering  should  be  put  on  before  shoveling  over  the 
sand  the  last  time.  When  trying  to  find  whether  the  sand 
needs  more  water  or  not,  the  hand  should  be  forced  into  the 
pile  to  get  some  sand  from  the  interior  from  which  to  deter- 
mine its  temper.  This  should  be  done  at  several  points. 
When  only  a  little  more  water  is  necessary  it  should  be 


TOOLS,  MACHINES,  AND  EQUIPMENT  71 

sprinkled  on  by  throwing  the  water  from  the  pail  with  the 
hand. 

The  molder  or  helper  should  learn  to  shovel  both 
right-  and  left-handed,  so  as  to  be  able  to  take  either  side 
of  the  heap  when  working  with  an  assistant. 

The  riddle  is  the  sieve  used  for  sifting  the  sand.  Its 
meshes  range  from  2  to  the  inch  to  16  or  32  per  inch. 
They  are  numbered  according  to  the  number  of  meshes 
per  inch,  as  a  No.  2  riddle  means  one  having  J  in.  meshes, 
a  No.  4  has  J  in.  meshes,  a  No.  16  has  A  in.  meshes,  etc. 
In  some  places  the  riddles  having  the  mesh  finer  than  ^  in. 
are  called  sieves. 

In  riddling  sand  by  hand,  the  riddle  should  be  held 
loosely  in  the  hand  and  carried  by  the  fingers,  so  that  the 
palm  of  the  hand  will  strike  the  rim  as  it  is  cast  from  side 
to  side.  Hitting  the  rim  of  the  riddle  in  this  way  jars 
loose  the  sand  that  sticks  to  the  riddle,  keeps  the  meshes 
open  better,  and  allows  the  sand  to  pass  through  more 
freely.  By  practice  in  holding  the  riddle  in  this  manner, 
a  rocking  swing  may  be  obtained  which  jars  the  riddle  at 
each  turn  and  carries  but  very  little  weight  on  the  fingers. 
It  is  often  found  of  advantage,  especially  in  fine  riddles,  to 
put  some  irons  in  with  the  sand,  as  gaggers,  etc.  These 
irons  scrape  the  wires  clean  and  add  to  the  jarring  of  the 
riddle. 

When  not  in  use,  the  riddle  should  always  be  hung  up  on 
a  nail  or  placed  on  the  sand  heap  with  the  screen  up.  If 
left  with  the  screen  resting  on  the  sand,  the  meshes  become 
clogged,  thus  hindering  the  passage  of  the  sand  through 
the  screen. 

There  are  many  forms  of  mechanical  sand  sifters.     The 


72  FOUNDRY  PRACTICE 

two  representative  forms  of  pneumatic  sifters  are  shown  in 
Figs.  92  and  94,  while  the  belt-driven  sifters  are  shown  in 
Figs.  99  and  100. 

Facing  sand  is  placed  next  to  the  pattern  in  making  a 
mold  in  order  that  the  sand  will  peel,  or  part,  from  the 
casting  freely  and  leave  a  smooth  surface.  Facing  sand 
contains  a  percentage  of  sea  coal  and  usually  new  sand,  de- 
pendent upon  the  kind  of  work  for  which  it  is  to  be  used. 

The  percentage  of  sea  coal  varies  greatly,  depending 
upon  the  thickness  of  metal  and  type  of  casting.  The 
limits  are  i  part  of  sea  coal  to  2  parts  of  sand,  and  i  part 
of  sea  coal  to  1 6  to  20  parts  of  sand.  The  limiting  pro- 
portions are  very  seldom  used.  The  usual  proportions  are 
from  i  to  6,  to  i  to  14  of  sand,  depending  on  the  thickness 
of  the  metal.  When  the  metal  is  thinner  than  J  in.  no 
facing  is  necessary.  Better  and  smoother  castings  are  ob- 
tained in  this  case  by  using  heap  sand  riddled  through  a 
fine  riddle  onto  the  pattern.  For  metal  between  J  in.  and 
i  in.  the  proportion  should  be  about  i  part  of  sea  coal  to 
12  or  14  parts  of  sand;  between  i  in.  and  2  in.,  i  part  of  sea 
coal  to  8  or  10  parts  of  sand;  above  2  in.,  i  part  of  sea  coal 
to  6  or  8  parts  of  sand. 

The  sand  used  in  the  facing  may  also  vary  in  its  propor- 
tion of  new  and  old  sand.  This  is  dependent  upon  the 
sand  used.  The  most  general  proportion  is  i  part  of  new 
sand  to  from  3  to  5  parts  of  old  sand.  Greater  percentages 
of  new  sand  may  be  used  on  heavy  work.  The  limiting 
case  is  a  facing  made  of  entirely  new  sand  for  the  cope  of 
very  heavy  work. 

It  is  not  always  the  thickness  of  the  casting  that  regu- 
lates the  strength  of  the  facing  sand.  There  are  many 


TOOLS,  MACHINES,  AND  EQUIPMENT  73 

other  things  to  be  considered :  (i)  whether  the  casting  is  to 
be  poured  with  hot  or  dull  iron;  (2)  the  distance  of  some 
parts  of  the  mold  from  the  gate;  (3)  the  time  it  will  take 
the  mold  to  become  filled  with  iron ;  (4)  whether  the  metal 
is  running  over  flat  surfaces,  and  (5)  is  covering  them 
slowly  or  quickly.  Then  again,  heavy  solid  castings  have 
become  "cold-shot"  owing  to  the  use  of  facings  that  were 
weak  in  proportion  to  the  casting,  caused  by  the  slow  rising 
of  the  metal  in  pouring.  Strong  facings  on  the  sides  of  a 
mold,  where  the  iron  enters  and  rises  slowly,  may  easily 
cause  heavy  castings  to  be  "  cold-shot."  Again,  the  square 
corners  of  castings  should,  in  general,  have  weaker  facings 
than  the  straight,  plain  surfaces.  The  lower  parts  of  deep 
molds  should  have  a  stronger  facing  than  the  upper  por- 
tion, because  the  metal  becomes  dull  while  rising  to  the  top 
of  the  mold.  If  the  facing  suitable  for  the  lower  portion 
were  used  at  the  upper,  the  casting  at  the  upper  part  would 
become  curly  or  partly  cold-shot  at  the  surface.  A  new 
sand  without  mixture  will  require  more  sea  coal  than  if  it 
were  mixed  with  old  or  common  heap  sand. 

A  thorough  mixing  of  the  facing  is  necessary.  If  the 
sea  coal  is  not  evenly  mixed,  it  often  causes  the  casting  to 
be  streaked,  veined,  or  cold-shot. 

In  mixing  by  hand  it  is  almost  impossible  to  distribute 
the  sea  coal  evenly,  therefore  it  is  important  that  it  should 
be  handled  several  times  in  order  to  come  as  near  as  pos- 
sible to  a  thorough  mixture. 

In  mixing,  the  old  and  new  sand  should  be  kept  as  dry 
as  possible  when  shoveled  over  in  order  to  mix  well.  The 
sea  coal  is  added  while  the  sand  is  spread  out  thin.  The 
whole  is  cut  over  once  or  twice,  then  riddled  through  a  No. 


74  FOUNDRY  PRACTICE 

6  or  8  riddle*  It  is  then  tramped  down  and  water  put  on 
to  give  the  proper  temper,  as  in  the  case  of  tempering  the 
heap  sand.  It  is  again  cut  over  to  mix  the  wet  and  dry 
sand,  then  riddled  through  a  No.  4  riddle.  It  is  now 
ready  to  be  riddled  onto  the  pattern.  The  mixture  should 
always  be  riddled  twice,  and  better  still,  three  or  four  times. 
It  is  best  to  use  sand  quite  dry  to  start  the  mixture,  as  when 
wet  the  sea  coal  sticks  in  small  balls  and  does  not  mix  well. 

In  large  foundries,  the  facing  sand  is  mixed  by  a  facing 
machine  which  gives  a  mixture  of  exact  proportions  and 
more  thoroughly  mixed  than  can  be  done  by  hand. 

The  frame  in  which  a  mold  is  made  is  called  a  flask. 
It  is  composed  of  two  or  more  parts.  The  bottom  part  is 
called  the  drag  or  nowel,  the  top  part  is  called  the  cope, 
and  the  intermediate  parts,  when  used,  are  called  the 
cheek.  Flasks  are  made  of  wood  or  iron. 

The  form  of  flask  used  for  small  patterns  when  the  pres- 
sure of  the  metal  is  very  little,  is  represented  in  Fig.  52. 
These  are  called  snap  flasks.  They  are  hinged  at  one 
corner  and  fasten  at  the  diagonal  corner  with  a  snap. 
The  mold  is  rammed  in  the  flask  and  when  ready  for  pour- 
ing the  flask  is  unsnapped  and  removed.  Thus  many 
molds  may  be  made  with  a  single  flask.  Before  casting, 
a  frame  the  same  size  as  the  flask  is  placed  around  the 
body  of  sand  and  a  weight  is  placed  on  top  to  prevent 
straining  the  mold  when  under  pressure. 

Small  flasks  up  to  14  in.  square  may  best  be  made  of 
iron,  without  bars  in  the  cope.  Those  larger  may  be  of 
either  wood  or  iron  to  suit  the  style  of  work  to  be  put  in  the 
flask.  When  the  flask  is  for  a  special  pattern  and  is  to  be 
used  for  that  only,  an  iron  flask  will  give  the  better  service 


TOOLS,  MACHINES,  AND  EQUIPMENT 


75 


and  is  far  cheaper.  When  for  general  patterns,  the  wood 
flask  has  many  advantages.  The  bars  may  be  fitted  to  a 
pattern  in  wood  with  little  time  or  expense,  and  for  a  class 
of  small  work  up  to  40  in.  square,  may  be  made  of  sufficient 
strength.  Larger  flasks  are  made  of  wood  having  bolts 
or  iron  bars  for  stiffening  the  cope.  When  but  a  single 
casting  is  desired,  even  to  very  large  castings,  the  flask  may 


FIG.  52. 

be  more  cheaply  made  with  a  wood  frame  and  iron  bars 
than  entirely  of  iron. 

In  manufacturing  shops  having  a  fixed  line  of  patterns, 
the  iron  flask  is  of  great  value.  The  first  cost  is  more  than 
that  of  a  wood  flask,  but  the  durability  far  exceeds  that  of 
wood.  The  bars  are  shaped  to  suit  the  pattern,  and  they 
remain  so;  while  a  wood  bar  burns  out  and  the  joint  of  the 
wood  flask  burns  away  leaving  holes  which  may  cause  a 
un-out,  thus  losing  the  casting.  The  iron  flask  is  much 


76  FOUNDRY  PRACTICE 

heavier  to  handle,  but  it  may  be  fitted  so  as  to  require  less 
anchoring  in  the  sand,  as  gaggers  and  soldiers  which  would 
be  required  in  a  wood  flask ;  thus  the  time  saved  in  molding 
will  more  than  equal  the  extra  help  necessary  to  handle  the 
flask.  Large  flasks  to  hold  castings,  as  cylinders,  engine 
girders,  bed  castings,  etc.,  and  flasks  to  be  used  many 
times,  should  be  made  of  iron  and  well  braced.  They  are 
then  ready  at  all  times  and  may  be  used  without  loss  of 
time  in  repairs. 

To  point  out  the  saving  resulting  from  the  use  of  a  flask 
instead  of  bedding  the  pattern  into  the  pit,  the  relative 
time  required  for  making  a  girder  casting  in  the  two  ways 
may  be  cited.  Before  the  flask  was  made  to  hold  the  pat- 
tern, it  was  bedded  into  the  pit  with  a  cope  to  cover  it.  It 
required  a  time  equivalent  of  14  days  for  a  molder  and 
helper  to  complete  and  cast  the  mold.  After  the  flask  was 
made  so  the  pattern  was  rammed  in  the  drag  and  turned 
over,  it  required  a  time  equivalent  of  9  days  for  a  molder 
and  helper  to  make  the  same  casting. 

Holders'  tools  vary  greatly  with  the  general  type  of 
work  that  the  molder  is  making.  The  number  of  tools 
necessary  for  a  molder  on  a  particular  type  of  work  may 
be  three  or  four,  while  on  intricate  work  many  tools  may 
be  required.  There  are  tool  manufacturers  who  can  fur- 
nish tools  of  nearly  any  size  or  shape  that  a  molder  may 
desire.  The  more  common  forms  are  shown  in  Fig.  53.. 
These  are  used  for  nearly  all  classes  of  work  and  are  made 
in  many  sizes  as  desired.  No.  i  is  a  round  point  finishing 
trowel;  No.  2,  a  square  trowel;  No.  3,  a  lifter  for  remov- 
ing sand  from  deep  and  narrow  parts  of  a  mold ;  No.  4, 
a  flange  and  bead  tool  for  slicking  special  round  surfaces; 


TOOLS,  MACHINES,  AND  EQUIPMENT 


77 


Nos.  5  and  6  are  two  forms  of  double-end  slicks  which 
represent  the  general  forms  out  of  greatly  varying  forms  of 
such  tools;  No.  5  has  an  oval  slick  at  one  end  with  the 
spoon  slick  at  the  other;  No.  6  has  the  square  and  heart 
slicks;  Nos.  7,  8  and  9  show  corner  slicks  of  which  No.  7 
is  for  round  corners,  No.  8  for  square,  and  No.  9  for  inside 
corners;  Nos.  10  and  n  are  pipe  slicks  for  cylindrical 


FIG.  53. 

surfaces;  No.  10  has  the  square  ends,  while  No.  n  has 
the  safe  end  for  a  corner  slick. 

The  success  of  making  the  mold  and  obtaining  a  good 
casting  is  dependent  mainly  upon  the  manner  of  ramming 
the  sand  to  form  the  mold.  Hard  spots  in  the  sand  cause 
scabs,  and  soft  spots  cause  swells.  Unevenness  of  ram. 
ming  causes  similar  unevenness  in  the  casting. 

In  ramming  the  drag,  the  flask  should  be  filled  to  a 


78  FOUNDRY  PRACTICE 

depth  of  from  5  to  6  inches,  ramming  first  around  the  edge 
of  the  flask,  then  next  to  the  pattern,  and,  lastly,  the  por- 
tion between,  using  the  pein.  On  small  castings,  it  is 
rarely  necessary  to  ram  the  sand  over  the  pattern.  The 
pein  or  the  butt  of  the  rammer  should  never  strike  within 
an  inch  of  the  pattern,  as  it  will  cause  a  hard  spot  at  that 
point. 

In  deep  molds  the  succeeding  rammings  should  be  done 
by  filling  in  loose  sand  to  the  depth  of  about  6  inches,  and 
ramming  first  with  the  pein  then  with  the  butt  in  order  to 
give  the  mold  the  proper  degree  of  hardness. 

In  ramming  the  drag,  either  the  pein  or  the  butt  may  be 
used  as  soon  as  the  pattern  is  well  covered,  so  that  the  ram- 
ming is  not  near  the  pattern.  It  is  of  advantage  to  tramp 
the  sand  with  the  feet  before  butting,  as  that  more  quickly 
compresses  it  to  a  moderate  hardness  and  facilitates  the 
butt  ramming. 

In  ramming  the  rim  of  a  pulley,  the  rammer  should  be 
directed  away  from  the  pattern  to  prevent  scabbing  the 
rim. 

The  larger  the  pattern,  the  harder  the  sand  may  be 
rammed.  When  of  a  depth  to  give  a  great  pressure  on  the 
bottom,  the  sand  must  be  rammed  harder  to  hold  the  pres- 
sure and  prevent  the  cracking  of  the  surface,  causing  rough- 
ness sometimes  called  "whiskers." 

On  patterns  of  the  round  column  type,  the  sand  may  be 
rammed  very  much  harder  than  in  other  cases,  if  the  metal 
is  to  be  thick.  It  is  very  important  to  have  these  rammed 
evenly,  as  unevenness  will  cause  defects  in  the  casting; 
even  though  it  is  not  of  a  hardness  at  any  point  which 
would  be  detrimental  were  the  entire  mold  of  that  hardness. 


TOOLS,  MACHINES,  AND  EQUIPMENT  79 

The  softer  the  sand  can  be  left  and  still  hold  the  casting 
in  proper  form,  the  less  is  the  liability  of  losing  the  casting. 
The  sand  must  be  hard  enough  to  hold  its  shape,  but  after 
that  the  risk  of  loss  in  casting  is  increased  as  the  hardness 
is  increased. 

In  ramming  the  cope  where  there  are  no  bars,  the  sand 
is  filled  in  to  a  depth  of  about  six  inches  and  rammed 
around  inside  the  flask,  then  the  remaining  portion  is 
rammed  evenly  with  the  pein.  The  butt  should  not  be 
used  in  the  cope  until  the  entire  flask  is  rilled,  then  the 
last  ramming  on  top  is  done  with  the  butt.  If  the  butt 
is  used  before  this  it  causes  a  hard  surface,  so  that  the 
sand  does  not  unite  in  the  succeeding  ramming  and  is 
liable  to  fall  out  when  the  cope  is  turned  over.  When 
the  cope  has  bars,  each  division  enclosed  by  the  bars  is 
rammed  separately  as  a  small  cope,  but  all  the  divisions 
must  be  of  an  even  hardness.  The  successive  rammings 
are  made  by  filling  in  about  six  inches  at  a  time  and 
ramming  with  the  pein. 

The  proper  manner  of  holding  the  floor  rammer  while 
ramming  is  to  grip  the  rod  connecting  the  pein  and  but! 
with  one  hand  above  the  other.  Never  hold  the  rammer 
with  one  hand  on  top  of  the  upper  end  of  the  rammer,  as  it 
will  jar  the  operator,  and  it  is  harder  to  do  good  ramming 
while  in  this  position. 

The  proper  venting  of  a  mold  is  of  as  great  importance 
as  any  part  of  the  process.  If  at  any  point  the  venting  is 
insufficient  to  carry  off  the  gases,  the  metal  will  blow  and 
spoil  the  casting. 

The  air  in  the  mold,  when  the  metal  is  being  poured, 
must  be  able  to  escape.  This  is  provided  for  in  some 


80  FOUNDRY  PRACTICE 

cases  by  the  riser,  but  often  the  vents  are  depended  upon 
for  this  purpose.  The  water  in  the  sand  is  evaporated  as 
steam  and  must  escape  through  the  sand.  The  continued 
addition  of  sea  coal  in  the  facing,  and  flour  and  plumbago 
in  the  mold,  increases  the  formation  of  gases  when  the 
metal  comes  in  contact  with  the  face  of  the  mold.  If  these 
cannot  escape  into  the  sand,  they  force  an  opening 
through  the  molten  metal,  which  is  known  as  blowing.  To 
enable  the  gases  to  pass  through  the  sand,  the  mold  must 
be  properly  vented.  Some  sands  are  so  coarse  and  open 
that  they  require  much  less  venting  than  others  which  are 
fine  and  close  in  texture. 

Small  and  thin  castings,  rammed  lightly,  require  no 
venting.  In  casting  heavy,  thick  plates  the  drag  must  be 
well  vented,  but  the  cope  does  not  require  much  venting, 
although  it  is  always  best  to  vent  it.  In  venting  any  plain 
casting,  the  size  of  vent  wire  is  mainly  dependent  upon  the 
depth  of  sand  to  be  vented.  For  flasks  up  to  12  in.  in 
depth,  -J  in.  wire  serves  well.  The  exact  size  of  wire  used 
is  unimportant,  so  that  the  venting  is  close  enough  to  give 
free  escape  for  the  gases.  The  vent  wire  should  not  strike 
the  pattern  or  scrape  along  a  side,  as  it  forms  holes  that  the 
metal  may  flow  through  and  allows  the  metal  to  stop  up  the 
vent,  which  gives  the  same  condition  as  though  there  were 
no  vent.  The  bottom  board  should  be  put  on  the  drag  and 
rubbed  to  a  bearing,  then  removed,  and  the  surface  creased 
crosswise  by  striking  with  the  corner  of  a  stick  to  reach 
the  width  of  the  drag,  then  the  drag  vented.  The  creases 
form  openings  through  which  the  gases  may  escape  when 
the  drag  is  turned  over. 

For  small  castings,  the  cope  should  be  vented  through 


TOOLS,  MACHINES,  AND  EQUIPMENT  8l 

almost  to  the  pattern  to  give  free  escape  for  the  gases  and 
air.  For  larger  castings  it  is  often  advisable  to  leave  a 
layer  of  two  to  three  inches  next  to  the  pattern  without 
vents.  This  does  not  give  free  escape  for  the  air;  thus  a 
pressure  can  be  maintained  within  the  mold  while  pour- 
ing, which  prevents  the  drawing  down  of  the  cope. 

Many  molds  have  enclosed  bodies  of  sand  which  do 
not-  have  free  vent  connections  with  the  top  or  bottom 
of  the  flask,  as  anchors  in  pulley  molds,  centre  parts  in 
three -part  flasks,  or  large  green  sand  cores.  The  vent 
must  be  led  to  some  convenient  point  where  an  opening 
is  left  through  the  cope  for  the  gases  to  escape.  A  gutter 
may  be  cut  around  the  surface  of  the  body  of  sand  about 
three  or  four  inches  from  the  pattern  and  connected  to 
the  ,vent  opening.  Slant  vents  from  the  gutter  will  give 
free  vent  to  the  gases. 

In  some  molds  there  are  pockets  having  metal  on  all 
sides  but  one.  The  vent  must  be  led  away  through  this 
side  and  this  very  freely.  When  the  pocket  is  small,  a 
vent  rod  may  be  laid  in  it,  and  slant  vents  leading  to 
the  pattern  give  the  necessary  relief.  When  the  pocket 
is  of  large  size,  it  is  not  safe  to  depend  on  the  slanting 
vent.  In  these  cases  the  gases  are  collected  by  a  coke 
or  cinder  bed  laid  in  the  pocket  and  led  to  the  outside 
by  a  vent  pipe  or  large  vent  rod. 

In  some  patterns,  as  columns,  the  vent  may  be  led 
off  at  the  parting  instead  of  through  the  bottom  of  the 
drag.  After  the  flask  is  rammed-  up  and  the  cope 
removed,  vents  are  made  under  the  pattern  from  the 
surface  of  the  drag  at  a  distance  of  about  two  inches 
apart.  These  are  led  to  the  outside  by  cutting,  or 


82  FOUNDRY  PRACTICE 

scratching,  a  small  gutter  in  the  surface  from  the  vent  to 
the  flask. 

Pit  molds  and  all  floor  molds  must  be  provided  with 
a  cinder  bed  located  about  one  and  one  half  or  two  feet 
below  the  casting  to  provide  for  the  escape  of  the  gases 
of  the  lower  half  of  the  mold.  The  cinder  bed  is  con- 
nected to  the  surface  by  vent  pipes,  which  give  free 
passage  for  the  gases.  Very  deep  molds  may  have 
cinder  beds  located  at  different  levels  around  the  mold. 
The  gases  are  led  to  the  cinder  bed  by  freely  venting 
the  mold  so  that  the  wire  strikes  the  bed. 

Surtace  molds  require  much  better  venting  than  those 
covered  with  a  cope,  as  the  metal  gives  no  pressure 
except  its  weight;  thus  it  cannot  force  the  gases  against 
much  resistance.  Small  surface  molds  may  not  require 
venting,  if  the  sand  is  rammed  only  enough  to  prevent 
the  metal  cutting  when  poured.  Large  molds  must  be 
provided  with  a  cinder  bed  which  has  free  vent  to  the 
surface.  The  mold  must  be  well  vented  to  the  bed. 

When  two  parts  of  a  flask  are  to  be  lifted  apart  after 
the  sand  is  rammed,  it  is  necessary  to  make  the  surface 
at  the  parting  so  that  the  two  bodies  of  sand  will  not 
knit  together  but  separate  freely  when  the  flask  is  opened. 
In  order  to  ensure  the  parting,  the  surface  of  the  sand 
must  be  slicked  smooth  after  making  the  surface  harder 
than  the  other  part  of  the  mold  and  covered  with  a  part- 
ing sand. 

When  the  drag  is  turned  over  and  the  follow  board  is 
removed,  the  surface  is  gone  over  with  the  hand  and  sand 
tucked  in  wherever  soft  spots  are  found.  The  sand  is 
then  cut  away  to  the  parting  of  the  pattern  or  to  the 


TOOLS,  MACHINES,  AND  EQUIPMENT  83 

surface  of  the  part.  A  thin  coat  of  sand  is  then  riddled 
onto  this  surface  and  the  whole  slicked  to  a  smooth  face. 
The  additional  sand  compacts  the  surface  to  a  harder 
shell  and  should  not  be  easily  broken  by  the  ramming 
of  the  sand  that  rests  on  this  parting.  This  slicking 
must  not  be  carried  to  an  extent  of  causing  an  extra  hard, 
or  bricklike  face,  as  this  will  cause  defective  castings 
similar  to  hard  spots  in  ramming. 

Parting  sand  is  put  over  the  surface  in  a  thin  coating. 
All  parts  of  the  sand  must  be  covered,  for  any  spots  left 
bare  will  stick  and  not  give  a  clean  part.  Parting  sand 
used  for  this  purpose  may  be  any  fine,  dry,  sharp  sand, 
very  fine  cinders,  or  burnt  core  sand  from  the  burned 
cores  in  the  castings.  This  sand  is  most  convenient  on 
all  plane  surfaces  and  where  the  slope  is  not  so  great  that 
it  will  not  stay  on  the  entire  face.  In  cases  where  the 
dry  sand  will  not  cover  the  surface  well,  wet  sharp  sand 
makes  a  good  part.  The  fine,  sharp  sand  is  dampened 
until  the  sand  sticks  together,  then  it  is  put  onto  the 
surface  with  the  hand  or  slicked  on  with  a  tool.  It  often 
helps  to  dust  a  little  dry  parting  sand  over  the  wet  sand 
after  it  is  on  the  surface,  as  the  wet  sand  sometimes  sticks 
when  the  surfaces  are  lifted  apart. 

Parting  sand  and  burnt  core  sand  make  molding  sand 
coarse  and  weak,  as  it  loses  its  strength  to  hold  a  form 
when  rammed.  Too  much  of  the  parting  sand  will 
spoil  the  sand  for  the  mold. 

Gates  are  the  openings  through  which  the  metal  enters 
the  mold.  The  location  of  the  gate  makes  a  great  differ- 
ence in  the  resulting  casting.  A  mechanic  can  show  his 
ability  in  gating  properly  more  readily  than  in  any  other 


84  FOUNDRY  PRACTICE 

part  of  the  mold.  Many  castings  are  lost  just  because 
the  molder  is  not  particular  enough  in  locating  and 
cutting  his  gates. 

All  plain  castings  having  about  an  even  thickness, 
and  that  greater  than  the  runners,  are  gated  at  the  side 
and  present  little  or  no  difficulty.  As  thin  plates  having 
runners  heavier  than  the  casting  set  sooner  than  the 
runner,  they  cannot  be  gated  at  the  side,  because  when 
the  runner  cools  the  casting  will  be  strained  or  warped. 
A  good  form  of  gate  in  such  cases  is  that  known  as  the 
bridge  gate,  having  a  basin  above  which  is  connected  to 
the  mold  by  a  long  narrow  opening  through  which  the 
metal  enters.  This  gate  is  easily  broken  off  and  leaves 
the  casting  straight. 

On  any  casting  having  ribs  running  from  the  side  to 
the  bottom,  the  metal  should  be  directed  lengthwise  of 
the  rib,  in  preference  to  flowing  over  the  edge  of  the  sand, 
as  there  will  be  less  danger  of  the  metal  cutting  the  sand. 

The  thin  parts  of  a  casting  should  be  filled  as  quickly 
as  possible  after  the  metal  starts  into  them.  A  casting 
having  heavy  and  light  parts  should  be  gated  so  that 
the  thin  parts  can  be  filled  quickly,  and  not  rise  slowly, 
as  when  filling  both  the  heavy  and  light  parts  at  the  same 
time.  If  the  gate  is  placed  on  a  thin  part  so  that  the 
metal  flows  over  the  surface  of  the 'mold  into  the  heavy 
portion  of  the  casting,  the  inflowing  metal  will  become 
cooled,  and  as  it  rises  into  the  thinner  parts  it  is  liable 
to  become  cold-shot  or  form  seams,  which  spoils  the 
casting. 

The  gate  must  be  so  located  that  the  metal  will  not 
flow  over  a  sharp  bead  of  sand  which  may  be  washed 


TOOLS,  MACHINES,  AND  EQUIPMENT  85 

away.     This  difficulty  is  sometimes  overcome  by  use  of 
the  horn  gate. 

The  common  use  of  a  riser  on  small  castings  is  to 
allow  the  air  and  gases  to  pass  out  of  the  mold  while 
it  is  being  poured.  The  dirt  carried  into  the  mold  by 
the  inflow  of  metal  is  carried  on  the  surface  of  the  iron, 
and,  as  the  metal  rises  in  the  riser,  the  dirt  is  floated  out 
of  the  casting. 

On  large  castings  or  those  whose  shrinkage  is  great, 
the  riser  is  made  large  so  as  to  supply  metal  to  feed  the 
shrinkage.  The  riser  must  be  large  enough  so  that  it 
will  not  freeze  until  the  casting  itself  has  set.  If  the 
shrinkage  is  not  thus  taken  care  of,  the  casting  is  liable 
to  have  shrink-holes  in  it. 

The  location  of  the  riser  for  small  castings  is  not  of 
great  importance,  although  it  is  best  to  have  it  where 
the  dirt  is  most  liable  to  accumulate.  In  castings  where 
it  acts  as  a  feeder,  it  should  be  connected  as  near  as  pos- 
sible to  the  heaviest  part  of  the  casting.  In  castings  of 
such  a  size  as  to  require  feeding,  the  riser  is  placed  over 
the  heaviest  part  of  the  casting  and  it  becomes  a  feed- 
ing head.  In  this  case  the  casting  is  fed  by  a  feeding 
rod,  which  keeps  the  riser  from  freezing  until  the  casting 
sets.  This  process  is  called  feeding,  or  churning,  the 
casting.  In  some  cases,  as  cannons  or  rolls  which  are 
cast  on  end,  the  casting  is  made  longer  than  that  desired 
and  the  end  turned  off  in  the  lathe.  The  extra  length 
takes  the  place  of  the  feeding  head  and  is  known  as  a 
sinking  head.  In  this  case  the  casting  does  not  require 
feeding. 

Some  foundries  making  castings  only  up  to  the  me- 


86 


FOUNDRY  PRACTICE 


dium  weight  never  make  use  of  the  feeding  rod,  but, 
instead,  depend  on  the  riser  as  a  sinking  head  and  pour 
the  iron  as  dull  as  it  can  be  run  into  the  mold.  These 
castings  are  often  unsatisfactory  and  frequently  have 
shrink-holes  in  their  upper  surface. 

A  skim  gate  is  an  arrangement  of  gates,  risers,  and 
runners  leading  to  a  mold,  whereby  a  supply  of  pure 
metal  may  be  obtained,  and  the  impurities  remain  in 
the  riser.  An  ordinary  skim  gate  may  be  constructed, 


FIG.  54. 

as  in  Fig.  54.  The  molten  metal  enters  through  the  pour- 
ing gate  a  and  flows  through  the  runner  c  into  the  riser 
b.  The  impurities  come  to  the  top  in  the  riser  while 
the  pure  metal,  being  heavier,  remains  at  the  bottom  and 
flows  out  through  the  runner  d  into  the  mold  e.  The 
arrangement  of  the  gate,  runner,  and  riser,  as  shown  in 
the  plan  view,  is  for  the  purpose  of  giving  the  metal  a 
rotary  motion  while  rising  in  the  riser  b.  This  is  in- 
tended to  aid  the  separation  of  the  impure  metal,  sand, 
and  dirt  from  the  pure  metal.  The  runner  d  is  below 


TOOLS,  MACHINES,  AND  EQUIPMENT 


the  level  of  the  runner  c.  The  cross-section  of  c  must 
be  greater  than  that  of  d  to  ensure  keeping  the  riser  b 
full  while  the  metal  is  being  poured.  Good  results  and 
sound  castings  are  obtained  by  the  use  of  this  arrange- 
ment for  the  gate. 

The  top  gate  with  the  pouring  basin,  shown  in  Fig.  35, 
forms  a  good  skimming  gate.  It  is  upon  the  principle 
that  the  pure  metal  being  heavier  flows  into  the  mold 
from  the  bottom  of  the  basin,  while  the  impurities  remain 


FIG.  55- 

at  the  top.  In  pouring,  the  basin  must  be  kept  full  so 
that  the  metal  enters  the  gate  from  the  bottom  instead 
of  from  the  surface  of  the  metal  in  the  basin.  The  only 
time  when  dirt  can  be  carried  into  the  mold  is  before  the 
basin  is  full.  The  dirt  is  carried  ahead  of  the  metal. 

The  preceding  arrangements  are  formed  by  the  gate 
sticks,  gate  cutter,  and  trowel.  A  very  convenient  de- 
vice for  forming  a  skim  gate  is  by  use  of  a  pattern,  as 
shown  in  Fig.  55.  This  pattern  is  rammed  up  in  the 
drag  with  the  pattern  to  be  molded.  The  portion  marked 


88  FOUNDRY  PRACTICE 

A  is  a  core  print.  After  drawing  the  pattern,  the  core 
B  is  placed  in  the  prints.  The  metal  entering  at  C  is 
given  a  rotary  motion  under  the  riser  placed  at  D  where 
the  impurities  rise.  The  pure  metal  flows  under  the  core 
into  the  mold  through  E. 

There  are  few  things  in  connection  with  making  a 
mold  that  are  of  greater  importance  than  the  construc- 
tion of  the  pouring  basin,  gate,  runner,  and  riser.  Skill 
is  necessary  to  be  thoroughly  successful  in  their  construc- 
tion. In  these,  the  washing  or  cutting  away  of  the  sand 
by  the  force  of  the  falling  metal  is  most  likely  to  occur. 
When  this  takes  place,  great  damage  is  likely  to  result 
to  the  casting.  If  the  molder  should  slight  any  other 
portion  of  the  mold,  he  may  still  get  a  casting  which 
would  pass  inspection;  but  any  neglect  or  ignorance  in 
the  construction  of  the  pouring  basin,  gates,  or  runners 
will  usually  spoil  the  casting.  When  the  sand  in  these 
cuts  or  breaks,  the  loose  sand  flows  with  the  metal  into 
the  mold  and  causes  a  dirty  casting.  Great  care  should 
be  taken  to  have  the  sand  well  tempered  for  the  con- 
struction of  a  pouring  basin.  To  make  a  reliable  pour- 
ing basin,  the  sand  should  be  rammed  evenly  into  the 
box,  or  frame,  and  the  basin  cut  out  with  the  trowel. 
This  ensures  an  even  solidity  to  the  sand  and  prevents 
cutting  or  washing. 

Gaggers  are  L-shaped  irons  used  by  molders  to  an- 
chor the  sand  into  the  flask.  The  lower  end  of  the 
gagger  is  called  the  "heel,"  and  varies  in  length  from 
two  to  six  inches,  to  suit  different  conditions.  The  other 
portion  of  the  gagger  may  be  of  any  length  to  suit  the 
depth  of  flask  in  which  it  is  used.  Some  gaggers  are 


TOOLS,  MACHTNES,  AND  EQUIPMENT  89 

made  with  a  short  hook  bent  at  the  upper  end  for  hook- 
ing over  the  bar  of  the  cope  to  ensure  firmness  in  lifting. 
They  are  made  either  of  wrought  or  cast  iron.  Wrought 
iron  is  preferable,  for  in  some  places  it  is  necessary  to 
bend  the  gagger  to  suit  the  particular  conditions. 

Gaggers  are  of  great  assistance  in  securing  sand  into 
a  flask  and  in  many  cases  are  indispensable.  To  obtain 
a  good  lift  in  a  cope  without  gaggers,  requires  the  bars 
to  be  in  very  good  condition  and  to  come  near  to  the 
parting.  With  gaggers,  the  sand  may  be  anchored  with- 
out the  bars  being  new  for  each  special  casting. 

The  strength  with  which  the  gaggers  hold  the  sand 
depends  upon  the  manner  in  which  they  are  set.  When 
properly  set  they  hold  with  great  efficiency.  When  set 
wrongly,  they  only  add  weight  tending  to  pull  the  sand 
down  or  cause  a  drop-out. 

The  gagger  should  be  so  placed  that  the  heel  comes 
near  to  the  parting  of  the  sand  to  be  lifted  and  should 
be  parallel  to  it.  The  length  of  the  gagger  should  come 
against  the  bar  or  frame  of  the  flask,  as  shown  at  A  in 
Fig.  17.  It  is  not  always  necessary  to  have  the  gagger 
stand  vertical,  although  that  is  the  best  position.  Odd 
slopes  may  often  be  accommodated  by  slanting  the 
gagger  or  bending  the  heel.  Oftentimes  mistakes  are 
made  in  setting  gaggers  improperly  and  cause  trouble. 
A  few  ways  of  setting  gaggers  so  they  do  not  hold  as 
desired  are  shown  in  Fig.  17.  At  B  the  gagger  will  hold 
the  sand  above  all  right,  but  the  sand  below  is  liable  to 
drop.  In  this  cope  the  desired  end  could  be  accom- 
plished by  placing  the  gagger  against  the  bar  at  right 
angles  and  have  the  heel  parallel  to  the  face  of  the  slope. 


po  FOUNDRY  PRACTICE 

At  C  the  heel  comes  onto  the  slope  rightly,  but  the  length 
of  the  gagger  does  not  come  against  a  bar,  therefore  it 
does  not  hold  anything.  In  almost  every  case  the  gagger 
would  drop  down  when  the  cope  is  lifted  off.  At  D  the 
gagger  is  placed  at  a  slight  slope  to  the  bar  and  its  heel 
parallel  with  the  parting.  This  will  usually  hold  quite 
well,  but  is  not  strong  nor  a  good  way  to  set  the  gagger. 
The  holding  power  depends  upon  the  sand  pressing  the 
gagger  against  the  bar  firmly  and  compressing  closely 
around  it.  Another  mistake  sometimes  made  in  setting 
gaggers  is  to  have  several  located  in  a  corner  against  one 
another  and  the  heels  radiating  in  different  directions  to 
hold  in  a  difficult  place.  The  sand  can  not  compress 
around  all  the  gaggers  or  hold  them  firmly  together. 
Part  of  them  are  held  only  by  the  friction  of  one  on  the 
other,  which  is  insufficient,  and  will  drop  out. 

The  number  of  gaggers  needed  is  dependent  upon  the 
sand  used  and  the  width  and  depth  of  the  body  of  sand 
lifted.  When  holding  a  corner  or  edge  of  sand  by  a 
gagger,  have  the  gagger  as  near  as  possible  to  the  edge 
and  parallel  with  it.  Always  be  sure  the  gagger  is  covered 
with  at  least  a  thin  coating  of  sand.  If  not,  the  iron  is 
liable  to  cause  an  explosion  when  coming  in  contact  with 
the  wet  rust.  Before  setting  in  the  sand,  the  heel  of 
the  gagger  must  be  wet  in  clay  wash  or  flour  paste. 
Otherwise  the  sand  will  not  stick  to  it.  Have  at  least 
two-thirds  of  the  length  of  the  gagger  come  against  the 
bar,  and  have  the  gagger  as  long  as  the  cope  will  allow. 

Soldiers  are  wooden  strips  or  pieces  placed  in  the  sand 
to  anchor  the  body  together.  They  are  made  of  size, 
length,  and  shape  to  suit  the  case  where  they  are  to  be 


TOOLS.  MACHINES,  AND  EQUIPMENT  91 

used.     Oftentimes  soldiers  are  placed  beside  bars  to  hold 
hanging  bodies  of  sand,  instead  of  having  special  bars. 

The  holding  power  of  soldiers  is  much  greater  than 
that  of  rods  or  nails,  as  the  sand  packs  against  their  un- 
even surface  and  will  not  give  without  tearing  up  the 
entire  body  of  sand.  This  will  be  fully  appreciated  if 
you  try  to  pull  a  soldier  out  after  it  is  rammed  into  the 
sand.  The  customary  use  is  for  holding  small  bodies  of 
sand  that  can  not  be  held  by  gaggers.  It  is  not  neces- 
sary to  have  the  soldier  come  against  a  bar.  It  holds 
firmly  when  in  the  body  of  the  sand  itself. 

In  setting  soldiers,  they  should  have  the  lower  end  wet 
in  clay  wash  and  pressed  down  to  place  in  the  sand  before 
ramming.  The  sand  should  be  in  a  loose  coating  of 
about  one  inch  over  the  parting  to  be  soldiered,  then 
when  the  soldier  is  placed,  some  sand  will  remain  below 
the  wood,  but  there  should  not  be  a  thick  coating  that 
may  fall  away  after  the  pattern  is  removed.  The  main 
precaution  is  to  be  sure  that  the  wood  is  covered  by  sand 
and  not  have  that  coating  such  that  it  may  fall  away 
and  expose  the  soldier.  In  case  the  soldier  is  exposed 
to  the  mold,  the  molten  metal  will  ignite  the  wood,  giving 
gases  that  can  not  escape  fast  enough,  thus  causing  the 
metal  to  blow.  This  sometimes  throws  the  metal  for  a 
great  distance,  endangering  the  safety  of  the  men  near 
by.  Even  a  very  thin  coat  of  sand  will  prevent  the  blow- 
ing from  the  soldier. 

The  points  or  corners  of  a  mold  are  usually  held  by 
nails  or  rods.  When  a  body  of  sand  comes  under  the 
pattern,  the  nails  or  rods  are  set  similarly  to  soldiers  and 
rammed  into  the  sand.  When  the  pattern  is  liable  to 


92  FOUNDRY  PRACTICE 

tear  in  drawing  or  a  body  of  sand  is  not  strong  in  itself, 
it  should  be  well  nailed  when  being  rammed. 

Green  sand  cores  which  are  exposed  at  the  parting 
may  best  be  nailed  after  the  flask  is  rammed,  for  then 
the  nail  head  supports  the  surface  of  the  sand  while  the 
nail  strengthens  the  entire  body  of  the  core.  Whenever 
there  is  doubt  of  the  strength  of  a  corner  or  core,  be  sure 
to  secure  well  by  nails. 

Where  the  mold  is  of  such  shape  as  to  endanger  the 
metal  cutting  at  any  point,  the  part  should  be  well  nailed 
after  the  pattern  is  removed,  leaving  the  heads  of  the 
nails  exposed.  A  few  nails  placed  where  a  corner  or 
surface  is  liable  to  cut  or  wash  by  the  inflowing  metal 
will  prevent  the  washing  away  of  the  sand  and  will  secure 
the  surface  in  a  surprising  degree. 

Rods  are  often  rammed  in  the  sand  to  strengthen  and 
bind  a  body  of  sand  that  must  resist  a  pressure  from  the 
metal.  Any  large  green  sand  core  must  be  well  rodded 
to  give  the  mass  strength  and  firmness.  When  the  sur- 
face of  a  green  sand  mold  must  resist  strong  pressure 
of  the  metal,  the  sand  must  be  well  tied  together  with 
rods.  In  a  pit  mold  for  fly  wheels,  the  head  in  the  risers 
gives  a  head  on  the  sand  of  from  2  ft.  to  4  ft.,  which 
means  a  pressure  per  square  inch  of  from  8  to  14  pounds. 
This  is  resisted  by  rods  laid  close  together  in  the  sand 
when  the  mold  is  rammed.  In  pockets  having  metal 
under  a  portion  of  them,  giving  a  strong  lifting  pressure, 
rods  are  laid  in  to  take  up  the  strain  and  secure  the 
pocket  firmly. 

A  molder's  skill  is  shown  in  his  ability  to  patch  a 
mold,  much  more  than  in  any  other  part  of  his  trade. 


TOOLS,  MACHINES,  AND  EQUIPMENT  93 

In  some  cases  patching  and  botching  are  synonymous, 
but  with  a  good  molder  the  latter  is  not  known.  Many 
patterns  can  not  be  removed  from  the  sand  without  more 
or  less  tearing  of  the  mold,  and  many  old  patterns  are 
used  that  an  unskilled  man  would  think  impossible  to 
get  a  good  casting  from.  A  good  molder  will  be  able 
to  repair  a  mold  that  seems  almost  completely  ruinc-J 
when  the  pattern  is  removed,  and  to  get  as  good  a  cast- 
ing as  though  the  pattern  were  perfect  and  he  secured  a 
good  draw ;  the  difference  being  mainly  in  the  time  neces- 
sary to  finish  the  mold. 

Practice  and  experience  with  different  cases  and  con- 
ditions can  alone  fit  a  man  to  cope  with  cases  requiring 
much  patching,  but  we  can  offer  a  few  suggestions  that 
may  be  helpful  to  the  beginner.  When  the  sand  is  dry 
or  tempered  properly  for  the  main  body  of  the  mold, 
it  is  nearly  impossible  to  patch  the  sand  at  corners  or 
difficult  places.  To  begin,  then,  the  part  to  be  patched 
should  be  dampened  with  the  swab,  being  careful  not 
to  wet  the  sand  so  as  to  cause  the  casting  to  blow.  In 
patching  a  corner,  place  a  tool  or  a  straight  face  against 
one  side  and  press  the  sand  in  at  the  other.  A  good 
corner  can  not  be  made  with  a  single  tool  alone.  Sand 
pressed  on  with  the  fingers  may  be  added  to  and  will 
hold  firmly.  When  put  on  with  a  trowel,  a  surface  is 
made  which  will  not  unite  well  with  the  sand  put  on  after- 
wards. Patching  done  with  the  fingers  will  not  cause  a 
scab  on  the  casting,  but  slicking  a  patch  may  act  similarly 
to  being  rammed  too  hard  at  that  point.  Where  much 
sand  is  to  be  put  on,  put  nails  in  the  place  to  be  patched 
so  the  heads  will  come  a  little  below  the  finished  surface. 


94  FOUNDRY  PRACTICE 

The  nails  help  to  hold  the  sand  while  putting  it  on  and 
secure  the  patch  after  it  is  finished.  Whenever  the 
patched  part  is  quite  large,  it  should  be  well  nailed  after 
finishing,  so  that  the  heads  come  flush  with  the  surface. 
In  patching  down  in  a  mold,  sand  may  be  put  on  by 
pressing  small  balls  of  sand  onto  a  tool  so  that  it  will 
carry  its  weight,  then  lower  to  the  desired  place  and 
lightly  slick  on. 

In  finishing  the  mold,  the  entire  surface  must  be  closely 
examined  to  be  sure  that  it  conforms  to  the  casting  de- 
sired. The  loose  sand  at  the  edges  must  be  pressed 
back  to  place  or  removed  so  that  it  will  not  fall  into  the 
mold  when  the  flask  is  closed,  thus  causing  a  dirty  cast- 
ing. All  loose  sand  in  the  path  of  the  inflowing  metal 
must  be  removed.  Be  sure  the  runners  are  made  so  that 
the  sand  will  not  wash  when  pouring  the  mold. 

The  last  thing  before  closing  a  mold,  a  molder  should 
see  that  all  loose  sand  is  removed  and  the  mold  is  clean. 
If  portions  of  the  mold  are  dark,  light  may  be  thrown  in 
by  a  small  hand  mirror  which  may  be  turned  so  as  to 
light  the  desired  parts. 

Thin  and  weak  patterns  have  oftentimes  to  be 
strengthened  by  pieces  which  are  stopped  off  in  the 
mold,  leaving  the  desired  shape  of  casting.  Where  a 
pattern  is  uniform  throughout  its  section  and  castings 
are  desired  of  different  lengths,  a  pattern  is  made  for  the 
greatest  length  and  the  mold  is  stopped  off  to  the  desired 
length  for  the  casting. 

In  stopping  off  strengthening  pieces,  the  face  of  the 
sand  in  the  part  to  be  filled  is  cut  up  with  a  tool,  then 
filled  with  sand  and  tucked  with  the  fingers.  Fill  in 


TOOLS,  MACHINES,  AND  EQUIPMENT  95 

small  amounts  at  a  time  so  the  sand  will  be  of  the  same 
hardness  as  other  parts  of  the  mold.  When  within  about 
half  an  inch  of  the  finished  surface,  the  part  should 
be  well  vented  through  the  sand.  The  finished  face  is 
slicked  with  the  trowel,  being  careful  not  to  get  the 
face  too  hard. 

When  stopping  off  a  portion  of  the  pattern,  a  stop-off 
piece  which  conforms  to  the  pattern  at  that  point  is  laid 
in  and  the  end  formed  to  the  piece.  When  without  a 
stop-off  piece  the  end  is  formed  by  a  trowel  or  a  piece 
of  wood  and  the  sand  filled  in  to  close  that  part  of  the 
mold. 

The  face  of  the  sand  should  always  be  cut  so  the  sand 
pressed  onto  it  will  unite  and  hold  firmly.  When  the 
metal  is  not  to  cover  the  face  made  in  the  stopping-off, 
it  is  not  necessary  to  vent  the  sand  nor  to  be  so  particular 
in  obtaining  an  even  hardness;  but  it  is  always  advisable 
to  be  as  careful  with  this  as  in  cases  that  are  more  par- 
ticular. 

WTien  a  mold  is  filled,  the  metal  freezes  at  the  surface 
first.  The  bottom  solidifies  before  any  other  part,  then 
the  other  surfaces  where  the  heat  is  most  readily  carried 
off.  This  solid  surface  gives  a  fixed  form  which  resists 
any  force  tending  to  change  its  shape.  As  the  metal 
shrinks  upon  solidifying,  something  must  replace  this 
shrinkage.  After  the  outside  surface  is  set,  the  metal  is 
drawn  from  the  still  molten  centre  of  the  casting  to  re- 
place the  shrinkage.  This  gives  a  porous,  honey-combed 
centre  which  has  no  strength.  This  defective  condition 
is  prevented  by  feeding  hot  iron  to  the  centre  of  the 
casting  while  it  is  solidifying  to  replace  this  shrinkage. 


96  FOUNDRY  PRACTICE 

There  are  two  general  methods  of  feeding  a  casting: 
first,  using  a  sinking  head;  second,  feeding  by  use  of  a 
feeding  rod.  A  sinking  head  is  where  the  mold,  when 
standing  in  a  vertical  position,  is  made  longer  than  the 
desired  casting  and  of  the  same  size.  The  excess  length 
is  filled  with  metal  and  allowed  to  sink  to  replace  the 
shrinkage  of  the  casting  below.  This  excess  is  turned 
off,  giving  the  solid  casting.  To  greatly  reduce  the  work 
of  turning  off  a  large  part  of  a  casting,  the  feeding  head 
is  made  much  smaller  than  the  casting  and  kept  open  by 
means  of  a  feeding  rod. 

The  feeding  head  must  always  be  large  enough  to 
enable  it  to  be  kept  open  until  the  casting  below  has  set. 
When  the  feeding  head  is  small,  it  freezes  almost  before 
a  rod  can  be  inserted,  hence  does  not  accomplish  its  pur- 
pose. It  is  always  safe  to  expect  that  some  of  the  metal 
will  freeze  to  the  sides  of  the  feeder  all  the  time,  even  if 
the  metal  is  kept  in  motion  constantly;  hence  the  feeder 
must  be  increased  to  allow  for  this  in  proportion  to  the 
time  that  it  should  be  kept  open.  A  feeding  rod  can  not 
be  used  to  advantage  in  a  feeder  less  than  three  inches  in 
diameter.  This  can  be  kept  open  only  a  short  time, 
hence  becomes  ineffective  where  the  casting  below  re- 
quires quite  a  time  to  solidify.  Where  a  large  feeder 
cannot  be  used,  due  to  bars  or  to  conditions  that  cannot 
be  avoided,  a  small  one  may  be  made  to  keep  open  longer 
by  increasing  its  length  and  supplying  hot  iron  to  heat 
this  portion  above  that  of  the  casting. 

A  large  riser  or  feeder  may  have  a  much  smaller  open- 
ing into  the  casting  and  still  be  as  effective.  A  3-inch 
feeder  may  have  an  opening  into  the  casting  ij  inches  in 


TOOLS,  MACHINES,  AND  EQUIPMENT  97 

diameter  and  give  as  good  results  as  though  the  full  size 
of  the  feeder  were  opened  through.  This  allows  the  use 
of  a  much  larger  feeder  and  permits  of  its  removal  from 
the  casting  as  easily  as  the  smaller  one.  The  smaller 
opening  is  kept  from  freezing  by  use  of  the  feeding  rod. 

The  rod  should  be  heated  in  the  ladle  before  lowering 
into  the  feeder,  to  prevent  chilling  the  iron.  It  should  be 
lowered  slowly  into  the  mold  until  the  bottom  is  touched, 
then  lifted  two  or  three  inches  and  given  an  up-and- 
down  motion.  Due  to  this  motion  it  is  commonly  called 
"pumping,"  or  " churning,"  a  casting.  The  feed  rod 
should  not  strike  the  bottom  of  the  mold,  as  it  is  liable 
to  punch  a  hole  in  the  mold,  causing  a  bunch  on  the 
casting.  The  rod  should  be  held  at  one  side  of  the  centre 
and  moved  around  to  keep  as  large  an  opening  as  pos- 
sible at  the  entrance  of  the  feeder  into  the  casting.  A 
casting  properly  fed  will  freeze  from  the  bottom  and 
slowly  crowd  the  feed  rod  out  of  the  casting  until  at  last 
it  is  only  in  the  riser. 

The  job  of  feeding  a  casting  is  not  a  pleasant  one. 
The  direct  radiation  from  the  metal  and  the  burning 
gases  about  the  flask  make  it  very  hot  and  disagreeable 
work.  For  this  reason,  many  molders  will  freeze  up  a 
riser  long  before  the  casting  below  has  set.  It  is  very 
marked  that  often  in  feeding  a  number  of  the  same  cast- 
ings, poured  at  the  same  time,  part  of  the  men  will  have 
their  feeders  frozen  long  before  the  others  do.  Those 
who  froze  theirs  first  have  castings  the  same  on  the  sur- 
face as  the  others,  but  the  centres  would  be  very  different 
were  the  castings  cut  open.  The  man  keeping  his  feeder 
open  the  longest  has  the  strongest  and  most  solid  casting. 


98  FOUNDRY  PRACTICE 

The  size  of  the  rod  used  is  unimportant  except  when 
it  is  so  large  that  it  closes  up  the  feeder  rather  than  keep- 
ing it  open.  In  a  feeder  smaller  than  3  in.,  the  feeding 
rod  should  be  J-in.  For  larger  feeders,  the  rod  may  be 
increased.  A  f-in.  rod  is  most  commonly  used,  as  larger 
ones  become  too  heavy  to  handle  and  quickly  tire  the 
workman. 

The  proper  setting  and  venting  of  cores  is  an  im- 
portant factor  in  molding.  Cores  are  made  of  sand  with 
binders  which,  when  dry,  form  a  solid  mass  of  the  desired 
shape.  They  are  placed  in  a  mold  to  make  the  casting 
different,  in  part,  from  the  pattern.  When  burned  by 
the  molten  metal,  the  core  crumbles  and  leaves  the  cast- 
ing hollow  in  that  part.  The  core  may  be  made  to  form 
recesses,  to  hollow  out  the  inside,  or  to  make  holes  of 
desired  shape  through  the  casting. 

The  binders  which  hold  the  sand  together  in  the  core, 
the  entrained  gases  of  the  new  sand,  and  other  constitu- 
ents of  the  core,  burn  out,  forming  a  volume  of  gas  that 
must  be  allowed  to  escape  when  the  metal  comes  in  con- 
tact with  the  core.  If  the  gases  are  not  properly  carried 
off,  they  force  their  way  through  the  easiest  relief,  which 
may  be  through  the  molten  metal,  causing  blowing;  this 
spoils  the  casting,  making  the  body  spongy,  if  not  blow- 
ing nearly  all  the  metal  out  of  that  portion  of  the  mold. 

When  a  core  is  made,  vents  are  always  provided  to 
carry  the  gases  to  some  particular  points  where  they  may 
be  conducted  away  through  the  sand  of  the  mold.  A 
core  completely  surrounded  with  metal,  except  at  its  vent, 
must  be  well  provided  with  free  passage  for  the  gases. 
Cores  having  the  metal  only  on  one  face,  as  slab  cores 


TOOLS,  MACHINES,  AND  EQUIPMENT  99 

covering  a  plane  surface,  do  not  require  special  venting, 
as  the  sand  will  carry  off  the  gases  freely  enough.  Small 
cores  partly  surrounded  with  metal  do  not  require  special 
venting,  as  the  sand  will  be  sufficient  to  take  up  the  small 
amount  of  gases  given  off. 

Where  prints  are  provided  on  the  pattern  for  simple 
cores,  the  setting  of  the  core  is  a  simple  matter.  The 
vent  must  be  provided  for,  then  the  core  is  lowered  into 
the  print  recess  which  anchors  the  core  in  the  desired 
position.  Round  cores  having  a  print  at  both  ends  must 
be  set  into  the  drag  so  as  to  enter  the  print  of  the  cope 
without  tearing  up  the  top  of  the  mold.  This  can  be 
done  by  the  eye  in  lining  it  from  different  directions,  being 
sure  that  it  is  directed  vertically.  Horizontal  cores  have 
the  print  of  both  ends  to  rest  the  core  on.  The  cores 
thus  far  considered  are  held  in  position  by  the  print  recess 
in  the  mold. 

Many  forms  of  cores  have  prints  for  locating  the  core, 
but  nothing  to  hold  the  core  from  floating  when  the  metal 
is  poured  into  the  mold.  Small  cores,  as  those  for  making 
a  hole  in  a  depressed  lug,  may  be  anchored  by  placing 
nails  slantwise  into  the  sand  to  bear  against  the  core. 

Large  cores  resting  in  the  drag  are  held  down  by 
means  of  chaplets,  as  considered  under  the  setting  of 
chaplets  (Fig.  57). 

Many  cores  have  no  print  in  the  drag  but  have  one  in 
the  cope.  In  such  cases  the  cores  are  anchored  in  the 
cope  by  wires  so  as  to  hold  their  weight  before  the  mold 
is  poured;  then  when  the  metal  tends  to  float  the  core, 
the  sand  bears  the  stress.  In  green  sand  copes,  the  core 
may  be  anchored  by  running  a  soft  iron  wire  from  the 


100  FOUNDRY  PRACTICE 

loop  in  the  core  to  the  top  of  the  cope,  then  fastening 
firmly  to  a  cross  bar  or  to  a  rod  resting  on  the  cope  bars. 
In  dry  sand  copes  having  heavy  cores,  the  cores  are  often 
bolted  to  cross  beams  by  bolts  having  a  hook  to  enter  the 
loop  in  the  core. 

Cores  are  sometimes  of  such  form  or  weight  as  to  re- 
quire straps  for  lowering  them  into  the  mold.  Heavy 
cores  may  be  set  by  a  crane,  when  straps  are  used,  which 
bend  easily  to  prevent  tearing  the  sand  when  being  re- 
moved from  the  mold. 

Chaplets  are  used  for  anchoring  cores  into  a  mold 
when  the  cores  are  of  such  shape  that  they  are  not  prop- 
erly supported  by  the  sand.  The  forms  and  types  of 
these  chaplets  vary  greatly.  The  two  'main  types  are  the 
single-headed  and  the  double-headed  chaplets,  as  shown 
in  Fig.  56.  The  simple  form  of  single-headed  chaplet 
is  shown  at  a.  This  has  the  forged  head,  having  burrs  at 
N  to  secure  the  chaplet  more  firmly  in  the  metal.  The 
end  may  be  sharp  or  blunt,  to  suit  the  place  where  it  is 
to  be  used,  b  shows  a  stem  on  which  a  head  of  desired 
size  and  shape  may  be  riveted,  d  shows  the  double-end 
forged  chaplet.  These  are  made  of  any  desired  length 
between  outside  faces  varying  by  TV  of  an  inch,  c  is  a 
stem  for  a  double-headed  chaplet.  Any  size  or  form  of 
head  may  be  riveted  on  to  suit  particular  cases,  e  shows 
a  double-end  chaplet  and  nail.  The  nail  holds  the  chap- 
let  in  position  before  the  core  rests  on  it.  This  assists 
in  setting  in  some  cases.  The  one  shown  has  riveted 
heads,  making  use  of  a  stem  on  which  the  desired  heads 
are  placed.  /  gives  a  form  of  chaplet  made  of  cast  iron. 
This  is  a  cheap  double-end  chaplet  which  may  be  made 


TOOLS,  MACHINES,  AND  EQUIPMENT  IOI 


J  JY.' 


FIG.  56. 


102  FOUNDRY  PRACTICE 

where  it  is  used,  g  shows  an  adjustable  double-end 
chaplet.  It  is  threaded  into  both  heads  with  the  stem 
threaded  to  allow  the  adjustment.  The  chaplet  and 
stand  are  shown  at  h.  This  enables  quick  adjustment 
of  chaplets,  as  the  stand  is  rammed  in  the  drag  against 
the  pattern ;  hence  the  chaplet  may  be  dropped  into  place 
when  the  pattern  is  removed.  A  form  of  spring  chaplet 
shown  at  i  may  be  used  to  substitute  for  a  double-headed 
chaplet  and  springs  to  give  the  desired  distance  between 
faces. 

The  most  common  forms  of  chaplets  are  those  shown 
at  a,  b,  c,  and  d.  There  are  factories  making  these  of  all 
sizes  and  shapes.  They  may  be  purchased  at  a  lower 
cost  than  they  could  be  made  without  the  use  of  special 
machinery. 

In  using  chaplets,  a  few  precautions  should  be  ob- 
served. Chaplets  placed  in  a  mold  weaken  the  resulting 
casting  in  a  greater  or  less  degree.  It  is  always  prefer- 
able to  avoid  their  use  where  possible.  They  weaken  the 
casting:  first,  by  introducing  a  foreign  metal  into  the  cast- 
ing, thus  destroying  the  unformitiy  of  the  metal;  second, 
by  forming  blow-holes  or  porous  metal  about  chaplet;  and 
third,  by  failing  to  unite  with  the  metal,  thus  becoming 
loose  or  leaving  a  hole  in  the  casting.  These  evils  may 
be  greatly  reduced  by  proper  design  and  use.  The  first 
cannot  be  avoided,  but  may  be  made  small  by  using  chap- 
lets  of  proper  size  and  shape  to  cause  the  least  possible 
break  in  the  uniformity  of  the  metal.  The  second  may 
be  nearly  always  avoided  by  proper  care  in  regard  to  the 
condition  of  the  surface  of  the  chaplet.  Moisture  on  the 
chaplet  holds  the  metal  away,  causing  blow-holes.  Rust 


TOOLS,  MACHINES,  AND  EQUIPMENT  103 

makes  the  metal  boil  and  blow,  causing  porous  metal  to 
form.  The  coating  on  the  chaplet  must  be  such  that  the 
iron  will  unite  with  it  and  lie  quiet.  Red  lead  put  on 
with  benzine  makes  a  good  coating.  A  tinned  surface 
gives  the  best  satisfaction  for  this  purpose. 

The  third  evil  may  be  avoided  by  so  shaping  the  chap- 
let  that  the  metal  will  adhere  closely  and  bind  itself  to 
the  chaplet.  This  may  be  done  by  having  notches  or 
depressions  in  the  stem,  as  shown  at  e,  Fig.  56,  or  by  barbs 
or  burrs,  as  N  on  a.  In  some  cases  the  thickness  of  the 
metal  where  the  chaplet  is  placed  is  not  sufficient  to 
ensure  a  firm  hold  on  the  chaplet.  The  thickness  should 
be  increased  around  the  chaplet  by  cutting  away  the  sand, 
forming  a  button  having  the  chaplet  in  its  centre. 

The  effective  strength  or  holding  power  of  a  chaplet 
is  dependent  upon  the  way  it  is  set  in  the  mold  and  the 
manner  of  wedging  it  after  the  flask  is  clamped.  Many 
castings  are  lost,  due  to  improper  setting  of  the  chaplets. 
The  chaplet  must  have  a  firm  bearing  on  the  core  and 
the  pressure  it  is  to  resist  must  act  directly  against  its 
length.  When  so  placed  that  the  pressure  tends  to  move 
it  sidewise,  the  resisting  power  is  only  that  of  the  sand 
around  the  chaplet. 

The  chaplet  set  in  the  drag  must  come  to  a  bearing 
where  it  is  to  remain.  Those  in  the  cope  extend  through 
and  are  held  against  the  core  by  wedges  or  weights  from 
above.  Where  the  flask  has  a  bottom  board,  the  chaplets 
set  in  the  drag  may  be  pointed  and  driven  into  the  bot- 
tom board,  as  shown  at  a  and  d,  Fig.  57.  The  head  of  the 
chaplet  should  conform  to  the  shape  of  the  core.  If  the 
head  is  not  shaped  the  same  as  the  core  at  the  point  of 


IO4 


FOUNDRY  PRACTICE 


bearing,  the  chaplet  may  cut  into  the  core,  thus  not 
holding  it  in  the  proper  position,  or  the  bearing  may  be 
on  one  side  of  the  chaplet,  which  may  tip  it  over.  Where 
the  sand  is  very  deep  below  the  point  where  the  chaplet  is 
to  be  placed,  or  there  is  no  bottom  board  to  drive  the 
chaplet  into,  a  block  may  be  rammed  into  the  sand,  as  at 


FIG.  57- 

the  base  of  c.  The  chaplet  must  be  set  vertical,  for,  if 
slanting,  the  effect  will  be  that  shown  at  c.  This  chaplet 
has  bearing  only  at  the  edge  and  will  hold  but  little,  as 
the  sand  will  crush  beside  the  chaplet,  allowing  the  core 
to  move.  Where  many  chaplets  of  the  same  length  are 
to  be  set,  as  in  duplicate  work,  much  time  may  be  saved 
by  ramming  in  the  mold  the  chaplet  stand  shown  at  b. 


TOOLS,  MACHINES,  AND  EQUIPMENT  105 

When  the  pattern  is  removed,  the  chaplet  may  be  placed 
in  the  stand,  thus  saving  the  adjustment  of  height 
and  driving  to  a  firm  bearing,  as  required  in  previous 
cases. 

There  are  many  other  conditions  to  be  considered  in 
setting  chaplets  in  the  cope.  It  is  best  to  pass  a  vent 
wire  through  the  cope  at  the  point  where  the  chaplet  is 
to  be  placed,  then  gradually  increase  the  size  of  the  rod 
until  nearly  the  size  of  the  chaplet,  when  it  may  be  pressed 
through  the  sand.  By  thus  slowly  increasing  the  size 
of  the  hole,  the  sand  is  compressed  and  not  cracked  or 
loosened,  as  may  be  done  when  too  great  a  pressure  is 
exerted  in  inserting  a  large  rod  or  chaplet.  The  chaplet 
should  be  drawn  out  when  first  inserted  and  the  hole 
reamed,  as  shown  at  o.  This  avoids  the  danger  of  the 
chaplet  pulling  down  the  sand  around  it,  as  at  g,  when 
the  chaplet  is  brought  to  a  better  bearing  or  wedged  down 
after  closing  the  cope.  Where  the  chaplet  bears  on  the 
slant  side  of  a  core,  the  head  should  be  bent  at  the  same 
angle  <\s  that  of  the  core,  as  at  i,  to  ensure  a  firm  bearing. 
Where  the  exact  shape  of  the  core  is  not  important,  a 
level  place  may  be  filed  into  the  core,  thus  allowing  the 
use  of  a  chaplet  having  the  head  at  right  angles  to  the 
stem.  The  chaplet  must  not  be  placed,  as  shown  at  h, 
Fig.  57,  for  it  is  liable  to  slide  down  the  slope,  thus  tend- 
ing to  displace  the  core  or  to  crush  the  sand  around  the 
stem  of  the  chaplet. 

Chaplets  may  be  properly  set  in  the  mold  and  arranged 
so  as  to  give  the  best  service  possible,  but  still  be  ren- 
dered ineffective  by  improper  wedging.  The  pressure 
resisted  by  chaplets  may  oftentimes  be  very  great,  espe- 


106  FOUNDRY  PRACTICE 

daily  in  large  molds.  The  wedges  must  be  so  placed  that 
the  pressure  may  be  held  without  any  tendency  to  move 
the  chaplet  sidewise.  This  cannot  be  done  with  one 
wedge,  as  that  gives  the  bearing  of  the  stem  onto  the  slant 
surface.  The  double  wedge,  as  at  m,  gives  a  firm  bear- 
ing on  a  surface  at  right  angles  to  the  stem  of  the  chaplet. 
The  taper  of  the  wedges  should  be  very  small  so  as  to 
avoid  slipping  when  the  pressure  is  exerted  on  them. 
Many  times  the  chaplet  is  too  short  for  using  wedges 
alone;  then  a  block  must  be  inserted.  This  is  as  good 
as  the  wedges  alone  when  the  surfaces  of  the  block  and 
the  wedges  are  kept  at  right  angles  to  the  chaplet.  Some 
of  the  incorrect  methods  of  wedging  with  a  block  are 
shown  at  n,  r,  and  s.  At  n  the  single  wedge  has  been 
driven  from  one  side,  thus  tilting  the  chaplet  so  that  it  is 
liable  to  move  over  when  the  pressure  acts  against  it.  The 
single  wedge  effect  is  also  shown  at  s.  It  is  a  poor  plan 
to  insert  wedges  from  opposite  sides  of  a  block  not  bear- 
ing on  each  other,  as  at  r  and  n.  The  block  is  quite  liable 
to  be  tilted  or  the  wedges  to  loosen  at  one  side,  causing 
damage. 

Another  improper  use  of  wedges  is  shown  at  t.  Here 
the  wedges  are  either  of  different  tapers,  or  so  placed  that 
the  one  resting  on  the  chaplet  has  a  bearing  only  at  the 
ends.  This  may  give  or  the  wedge  break  when  the 
pressure  is  applied.  Cast-iron  wedges  placed  in  this 
manner  on  heavy  work  have  been  broken,  thus  allowing 
the  core  to  rise. 

Wedges  made  of  hard  wood  give  good  satisfaction  in 
light  work.  Wrought  and  cast  iron  wedges  are  more 
reliable  and  may  be  used  in  any  case. 


TOOLS,  MACHINES,  AND  EQUIPMENT  107 

The  parts  of  a  mold  are  held  together  by  properly 
clamping  or  weighting  the  cope  and  cores  before  cast- 
ing. The  stress  upon  the  cope  due  to  the  molten  metal 
when  a  flask  is  poured,  is  dependent  upon  many  con- 
ditions. The  main  force  is  that  of  the  static  fluid  while 
the  metal  is  still  a  liquid.  A  second  force,  in  some 
cases  of  great  magnitude,  is  that  due  to  the  momen- 
tum of  the  metal  when  the  mold  fills  and  the  metal  comes 
up  in  the  riser.  This  force  may  be  inappreciable  in  many 
cases.  In  particular  cases  there  appears  to  be  a  force 
exerted  that  cannot  be  well  accounted  for,  but  which 
must  be  provided  against  when  liable  to  appear. 

The  static,  or  fluid,  pressure  on  a  cope  may  be  cal- 
culated directly.  Before  giving  the  method  of  determin- 
ing the  force,  let  us  understand  what  causes  this  force. 
The  metal  when  molten  is  a  fluid  the  same  as  water,  and 
it  passes  from  the  fluid  state  to  the  solid  when  the  tem- 
perature lowers  below  its  fusion  point,  the  same  as  water 
becomes  ice  as  soon  as  it  cools  below  32°  F.  or  o°  C.  The 
same  laws  hold  true  with  each  fluid  while  in  the  same 
state  of  fluidity.  Since  water  is  better  known,  let  us  con- 
sider that  we  are  handling  water;  then  by  the  change  of 
weight  we  will  have  the  conditions  existing  in  the  case  of 
molten  iron.  Any  body  lighter  than  water  will  sink  into 
its  surface  until  it  has  displaced  an  amount  equal  to  its 
own  weight.  In  order  to  press  the  body  still  further  into 
the  water  a  force  must  be  exerted  equal  to  the  weight  of 
the  water  displaced.  When  once  the  body  becomes  im- 
mersed only  a  slight  increase  of  the  force  will  sink  it  to 
any  depth.  This  additional  pressure  is  small  enough  so 
it  may  be  neglected  in  cases  that  we  consider.  This 


I08  FOUNDRY  PRACTICE 

gives  the  action  that  takes  place  upon  a  core  that  is  sur- 
rounded by  metal.  The  pressure  exerted  upon  any  sur- 
face by  the  water  is  due  to  the  area  of  the  surface  and 
the  height  of  the  water  above  that  surface.  In  fluids  the 
pressure  at  any  point  is  equal  in  all  directions  and  is 
transmitted  without  loss  throughout  its  entire  body.  Thus 
if  a  tank  be  tight  and  have  a  small  pipe  extending  directly 
above  it,  and  it  be  filled  with  water  until  the  pipe  is  partly 
filled,  the  pressure  on  any  cross-section  is  the  same  as 
though  the  tank  extended  at  its  maximum  size  and  were 
filled  to  the  same  level  as  that  in  the  pipe. 

The  amount  of  force  necessary  to  hold  down  a  core 
that  is  surrounded  with  iron  may  be  found,  since  it  will 
equal  the  difference  between  its  weight  and  that  of  an 
equal  volume  of  iron.  Sand  weighs  about  .06  Ibs.  per 
cubic  inch,  and  iron  weighs  .26  pounds.  The  difference 
between  the  two  is  therefore  .2  Ibs.  per  cubic  inch.  By 
finding  the  volume  of  the  core  in  cubic  inches  and  multi- 
plying .2  Ibs.  by  this  number  we  have  the  weight  neces- 
sary to  hold  the  core  down  when  the  mold  is  poured. 
If  the  core  has  metal  partly  around  it,  the  pressure  will 
be  the  same  as  that  exerted  on  the  sides  of  the  mold  at 
that  level. 

The  pressure  exerted  on  the  cope  will  be  that  due  to 
the  head  above  the  surface  of  the  cope  and  acting  on 
the  area  of  mold  which  the  cope  covers.  This  can  be 
more  plainly  understood  by  taking  a  particular  case,  as 
a  plate  whose  top  is  12  in.  by  24  in.,  and  having  a  cope 
1 6  in.  by  24  in.  and  6  in.  deep.  The  head  on  the  face  of 
the  cope  will  then  be  6  inches.  The  area  of  the  mold  is 
12X24,  or  288  square  inches.  The  volume  of  metal 


TOOLS,  MACHINES,  AND  EQUIPMENT  109 

which  would  be  equivalent  to  the  pressure  is  288X6,  or 
1728  cubic  inches.  Its  weight  will  be  1728 X. 26,  or 
499.28  pounds.  The  weight  of  the  cope  will  be  its  volume 
in  cubic  inches X. 06,  the  weight  of  a  cubic  inch  of  sand, 
or  26Xi6x6X.o6  =  ii3.76  pounds.  Therefore  the  addi- 
tional weight  required  upon  the  cope  will  be  449.28  — 
113.76=335.52  pounds. 

The  magnitude  of  the  force  due  to  momentum  cannot 
be  calculated  and  is  dependent  upon  the  style  of  gate 
and  rapidity  of  pouring.  If  the  mold  is  poured  slowly, 
the  metal  rises  slowly  and  comes  up  in  the  riser  easily, 
exerting  no  force  of  momentum.  If,  on  the  other  hand, 
the  metal  is  poured  in  rapidly,  and  the  mold  fills  quickly, 
the  moment  of  the  flowing  metal  has  to  be  overcome  by 
the  cope,  which  stops  its  flow  suddenly. 

The  style  of  gate  has  a  great  influence  upon  the  amount 
of  the  pressure  due  to  momentum.  If  the  metal  is 
poured  into  a  basin,  the  fall  of  the  metal  from  the  ladle 
is  broken  and  the  iron  enters  the  gate  with  but  little  force. 
Therefore  the  pressure  in  the  mold  will  be  practically 
that  due  to  a  head  the  height  of  the  metal  in  the  basin. 
When  the  metal  is  poured  directly  into  the  gate,  a  much 
greater  momentum  is  attained.  The  metal  falling  from 
the  ladle  into  the  gate  attains  a  velocity  and  consequent 
energy  which  is  exerted  upon  the  metal  in  the  gate. 
This  gives  a  pressure  almost  equivalent  to  that  produced 
by  a  head  the  height  from  which  the  metal  falls.  The 
allowance  necessary  to  cover  this  extra  force  makes  the 
safe  weight  one-half  larger  than  that  calculated  for  the 
statical  head.  This  will  take  care  of  all  other  force 
not  accounted  for. 


HO  FOUNDRY  PRACTICE 

Castings  are  often  ruined  by  putting  too  great  a  weight 
upon  the  cope  or  by  drawing  the  clamps  too  tight,  thus 
causing  a  crush  in  the  mold. 

In  clamping  a  cope,  the  main  idea  is  to  hold  the  flask 
firmly  together  so  it  cannot  strain  at  any  point,  allowing 
the  metal  to  run  out.  It  is  not  necessary  to  put  great 
pressure  on  the  cope  with  the  clamps  in  order  to  hold 
the  metal.  After  the  clamp  is  tight  so  it  cannot  give, 
any  additional  pressure  on  the  clamp  is  more  detrimental 
than  beneficial.  The  clamp  should  stand  nearly  straight 
and  be  tightened  onto  the  wedge  with  a  clamping  iron,  as 
shown  in  Fig.  9.  Clamps  should  be  placed  near  enough 
together  to  avoid  straining  the  flask  between  them. 

The  strength  of  a  clamp  throughout  its  central  part 
where  the  stress  is  tense  may  be  calculated,  allowing 
5000  Ibs.  per  square  inch  of  cross-section  for  cast  iron 
and  15,000  Ibs.  per  square  inch  for  wrought  iron.  The 
greatest  stress  on  the  clamp  is  at  the  corner,  and  that  is 
dependent  upon  the  leverage  to  the  bearing  point.  The 
corner  must  be  greatly  reinforced  to  make  it  equal  to  the 
other  part.  Wrought-iron  clamps  are  usually  made  by 
bending  a  bar,  which  makes  them  weaker.  The  force 
they  will  resist  is  that  necessary  to  bend  the  corner. 

The  volume  of  a  given  weight  of  iron  changes  as  it 
passes  from  the  liquid  to  the  solid  state.  This  diminution 
of  volume  upon  solidification  is  called  shrinkage.  The 
amount  of  shrinkage  varies  with  the  chemical  composi- 
tion of  the  iron.  The  average  shrinkage  is  an  eighth  inch 
to  one  foot  in  length.  This  shrinkage  is  allowed  for  in 
the  patterns  by  use  of  the  pattern  scale,  the  dimensions  of 
which  are  that  amount  in  excess  of  the  standard  scales. 


TOOLS,  MACHINES,  AND  EQUIPMENT  m 

The  volume  also  reduces  after  solidification  as  the  tem- 
perature reduces  to  that  of  the  atmosphere.  This  is  often 
treated  as  the  contraction  of  the  iron,  but  it  is  more  sim- 
ple to  combine  the  two  and  treat  it  as  shrinkage.  The 
feeding  of  large  casting  is  for  the  purpose  of  supplying 
metal  to  the  interior  of  the  casting  to  replace  that  drawn 
away  by  the  shrinkage  after  the  outer  shell  has  become 
set. 

Many  castings  are  ruined  by  holes  in  the  casting 
where  it  should  be  solid  and  filled  to  the  form  of  the  pat- 
tern. These  holes  may  be  from  either  or  both  of  two 
causes:  first,  the  casting  may  blow,  or  second,  the  shrink- 
age draws  away  the  metal  from  a  particular  point.  The 
defects  are  called  blow-holes  in  the  first  case  and  shrink- 
holes  in  the  second.  The  causes  of  the  first,  or  blow- 
holes, may  be  various.  It  is  the  gases  failing  to  escape 
from  the  face  of  the  mold  or  some  core  and  forcing  their 
way  through  the  molten  metal,  leaving  the  opening  when 
the  metal  sets.  A  few  causes  may  be  mentioned  which 
are  most  common:  too  wet  sand,  too  hard  ramming,  im- 
proper venting  of  sand  or  cores,  wood  or  rusty  iron 
coming  in  contact  with  the  molten  metal,  or  faces  such 
that  the  metal  will  not  lie  quietly  against  them.  These 
holes  are  characterized  by  rough,  irregular  surfaces,  and 
have  the  appearance  of  gas  enclosed. 

Shrink-holes  are  caused  by  the  drawing  away  of  the 
metal  to  replace  the  shrinkage  while  solidifying.  These 
are  caused  by  failure  to  supply  feeding  iron  to  the  heavy 
parts  after  the  surface  has  set.  It  may  be  due  to  the  form 
of  the  casting  or  to  insufficient  feeding  when  such  is 
provided.  The  point  where  such  a  shrink-hole  is  most 


112  FOUNDRY  PRACTICE 

liable  to  be  is  where  there  is  a  break  in  the  regular  sur- 
face of  the  casting,  as  under  a  feeding  head  which  was 
of  insufficient  size,  where  the  gate  or  riser  is  cut  into 
the  casting,  where  a  lighter  part  of  the  casting  joins  to 
the  heavier  part,  or  at  the  top  surface  when  no  weak 
point  is  adjacent. 

These  holes  are  characterized  by  smooth  holes  de- 
pressed into  the  casting  with  solid  bases,  or  depressions 
in  the  casting  having  the  appearance  of  a  shell  solidify- 
ing in  contact  with  the  face  of  the  mold,  then  drawn 
down  by  the  shrinkage.  When  the  shrink-hole  is  not  at 
the  surface  it  may  take  a  very  different  appearance.  The 
honeycombing  at  the  centre  of  large  castings  is  due  to 
the  shrinkage  drawing  the  metal  away  from  the  centre 
after  the  outer  shell  has  become  of  such  strength  as  to 
resist  the  shrinkage  strains. 

The  remedies  for  such  shrink-holes  are  to  make  feed- 
ing heads  of  ample  size  and  feed  the  casting  until  the 
shrinkage  is  provided  for,  to  have  the  feeder  connected  to 
the  heaviest  part  of  the  casting,  to  supply  a  feeder  where 
the  shrink-holes  appear,  or,  when  feeding  with  a  rod,  to 
keep  the  feeder  open  until  the  casting  is  set  by  supplying 
hot  iron  in  the  feeding  head. 

Burning  on,  or  casting  on,  is  the  uniting  of  two  parts 
of  a  casting  or  the  forming  of  a  new  part  onto  a  cast- 
ing. It  is  the  welding  of  the  cast-iron  parts.  In  order 
to  form  such  a  weld  the  face  of  the  casting  must  be  heated 
to  a  plastic  or  molten  state.  This  is  accomplished  by 
pouring  hot  molten  metal  over  the  surface  where  the 
weld  is  to  be  made,  until  it  starts  to  melt  or  becomes 
plastic. 


TOOLS,  MACHINES,  AND  EQUIPMENT  113 

Often  the  arms  of  pulley  castings  break  in  cooling. 
When  the  other  parts  are  sound,  the  arms  may  be  burned 
together,  forming  a  perfect  casting.  This  is  done  by 
chipping  away  the  edges  of  the  break  so  as  to  expose  the 
surfaces  of  the  casting.  The  pulley  is  laid  onto  a  sand 
bed  so  the  top  of  the  arm  is  level.  A  dry  sand  core  is 
fitted  about  the  arm  at  the  bottom  and  sides  of  the  break, 
leaving  its  top  entirely  exposed.  A  runner  is  made  to 
lead  the  overflow  away  to  pig  beds.  The  burning  is 
accomplished  by  pouring  a  constant  stream  of  metal 
onto  the  break  until  the  surfaces  become  plastic  or  molten. 
The  pouring  is  stopped,  leaving  the  opening  between  the 
cores  filled,  which  unites  the  broken  surfaces. 

The  excess  metal  is  chipped  off,  giving  the  repaired 
casting.  The  progress  of  the  burning  can  be  determined 
by  scraping  the  face  with  a  rod  while  the  metal  is  being 
poured  onto  it.  When  the  face  of  the  casting  begins  to 
melt  it  can  be  felt  to  soften  under  the  rod.  When  the 
hard  spots  are  felt,  the  inflowing  metal  should  be  directed 
onto  them  until  the  entire  surface  softens,  which  marks 
the  completion  of  the  process. 

The  method  of  casting  a  piece  onto  a  casting  may  be 
illustrated  by  forming  a  portion  of  the  bracket  onto  the 
column  shown  in  Fig.  43.  Consider  the  bracket  to  be 
broken  off  along  the  dotted  line  ab.  The  column  is  laid 
on  the  sand  so  the  face,  a,  is  level.  Dry  sand  cores  are 
fitted  to  enclose  the  bracket,  giving  the  desired  form,  with 
the  top  side,  a,  open.  A  small  hole  is  left  through  the  core 
at  b.  A  runner  is  led  from  this  hole  to  the  pig  bed.  The 
iron  is  poured  onto  the  broken  surface  at  the  rate  the 
opening  will  allow  it  to  escape.  The  stream  is  directed 


114  FOUNDRY  PRACTICE 

onto  different  points  until  the  entire  surface  becomes 
plastic.  The  opening  at  b  is  then  closed  with  a  clay  ball 
and  the  bracket  filled  with  metal,  which  forms  the  de- 
sired casting. 

Bench  molding  includes  the  light  work  where  the 
mold  is  made  upon  a  bench,  and  after  completion  the 
mold  is  placed  upon  the  floor  for  casting.  The  bench  is 
so  fitted  that  the  sand-pile  is  under  it  while  shelves  are 
attached  for  holding  the  tools  within  convenient  reach. 
The  bench  is  moved  back  over  the  sand-pile  as  it  is  used, 
while  the  molds  are  placed  in  front  in  a  convenient  ar- 
rangement for  pouring.  The  molder,  being  in  a  stand- 
ing position,  is  more  comfortable  and  can  produce  more 
molds  than  on  the  floor  in  a  stooping  position. 

The  snap-flask  is  especially  suited  to  this  class  of  work. 
Individual  flasks  of  small  sizes  are  also  used  on  the 
bench.  The  flasks  are  of  such  sizes  that  they  may  be 
handled  easily  from  the  bench  to  floor  after  the  mold  is 
finished.  Ordinarily  the  individual  flask  should  not  ex- 
ceed 1 6  inches  square. 

Bench  molding  is  used  extensively  in  brass  foundries. 
The  sand  is  mixed  and  tempered  in  a  box  or  trough 
within  convenient  reach  of  the  bench. 

Most  patterns  have  the  lines  of  parting  at  different 
levels  at  different  parts  of  the  pattern.  In  these  cases, 
if  the  pattern  were  laid  on  a  plain  board,  the  molder 
would  be  obliged  to  cut  away  the  sand  to  the  line  of 
parting  of  pattern  and  slick  the  surface  for  the  parting 
of  the  mold.  To  avoid  this  loss  of  time,  a  special  follow- 
board  is  made  which  conforms  to  the  pattern  and  forms 
the  desired  parting  surface  on  the  drag. 


TOOLS,  MACHINES,  AND  EQUIPMENT  115 

A  match  is  a  follow-board  made  from  new  sand  rammed 
hard,  core  mixtures,  or  any  convenient  material  that  will 
maintain  its  shape  firmly.  A  match  is  often  made  for 
the  present  use  for  a  special  order.  With  standard  pat- 
terns the  match  is  made  permanent  and  goes  with  the 
pattern.  A  permanent  match  may  be  cheaply  made  of 
core  mixtures.  The  preferable  mixture  is  that  of  linseed 
oil  and  fine  sand,  because  it  holds  its  shape  firmly  and  is 
not  affected  by  dampness. 

When  there  are  not  enough  castings  to  be  made  from 
a  pattern  to  pay  to  shape  a  special  follow-board,  and  the 
pattern  projects  into  the  cope,  it  is  often  desirable  to 
make  a  match  of  green  sand  in  the  cope  with  the  pattern 
at  its  proper  location.  The  drag  is  rammed  up  in  its 
position  on  the  cope.  When  turned  over  the  cope  is  re- 
moved, the  sand  is  cleared  away,  and  the  parting  of  the 
drag  is  prepared  for  ramming  the  cope. 

A  plain  board  is  used  as  a  turn-over  or  follow-board 
with  patterns  having  plain  surfaces  or  the  parting  nearly 
in  the  plane'  of  the  face  of  the  drag. 

Molding  machines  are  for  the  purpose  of  expediting 
the  operation  of  molding.  The  term  molding  machine 
does  not  mean  that  the  machine  will  do  the  work  of 
forming  a  mold.  Molding  machines  may  be  classified 
under  three  general  heads:  first,  the  machine  for  me- 
chanically drawing  the  pattern;  second,  the  molding 
press;  and,  third,  the  machine  with  press  and  mechanical 
drawing  of  the  pattern. 

In  the  first  class  of  machine,  the  sand  is  rammed  by 
hand  in  the  usual  manner.  When  ready  to  be  removed 
from  the  machine,  the  pattern  is  drawn  down  by  mechan- 


n6 


FOUNDRY  PRACTICE 


TOOLS,  MACHINES,  AND  EQUIPMENT 


117 


ical  means,  usually  a  lever  or  rack  and  pinion.  The  pat- 
tern is  drawn  through  a  stripping  plate,  which  prevents 
the  sand  from  tearing  and  makes  possible  the  perform- 
ing of  the  operation  more  rapidly.  The  hand  is  unsteady 
and  cannot  hold  the  pattern  so  as  to  move  it  out  of  the 
mold  perpendicular  to  its  face;  hence  it  takes  much  time 
and  skill  to  draw  the  pattern  without  tearing  the  mold. 


\ 


FIG.  59. 

This  type  of  machine  is  suited  to  a  wide  range  of  cast- 
ings. Many  manufacturers  of  molding  machines  are 
fitted  to  build  a  machine  for  a  very  great  variety  of  pat- 
terns. One  machine  of  this  class  is  shown  in  Fig.  58.  It 
is  for  making  pulleys  of  any  desired  size  and  width  of 
face  up  to  about  44  in.  diameter  with  24  in.  face.  The 
range  for  each  machine  is  about  12  in.  on  the  diameter; 


n8 


FOUNDRY  PRACTICE 


i.e.,  a  machine  will  make  all  sizes  from  6  in.  to  18  in.  in 
diameter.     The  changeable  parts  are  the  pattern  ring,  the 


arms,  and  the  stripping  plates  for  each  size,  as  shown  in 
Fig.  58.     The  cope  and  drag  are  rammed  on  the  same 


TOOLS,  MACHINES,  AND  EQUIPMENT  119 

machine,  and  the  pins  are  so  arranged  that  the  joint 
comes  together  correctly  when  the  flask  is  closed. 

The  machine  shown  in  Fig.  59  is  one  of  a  great  variety 


FIG.  61. 


of  machines  which  are  for  a  special  casting.  One  ma- 
chine forms  the  cope  while  the  other  forms  the  drag. 
These  two  machines  are  combined  in  one  for  some  pat- 


120 


FOUNDRY  PRACTICE 


terns;    then  each  flask  contains  two   castings.     Special 
flasks  are  required  for  all  this  type  of  machine. 
The  second  class  of  machine  performs  the  operation  of 


ramming  the  sand  in  the  flask,  while  all  the  other  opera- 
tions are  performed  by  hand.  Fig.  60  represents  a  press 
molding  machine,  or  "  squeezer."  The  machine  fulfills 
the  offices  of  the  bench  used  in  bench  molding,  and  also 


TOOLS,  MACHINES,  AND  EQUIPMENT 


121 


has  the  presser  head  which  compresses  the  sand  into  the 
flask  instead  of  ramming  by  hand.  The  work  handled  on 
these  machines  is  the  same  as  that  done  on  the  bench 
The  snap- flask  is  used  on  all  small  machines. 


FIG.  63. 

Fig.  6 1  represents  a  press  molding  machine  having 
pneumatic  connections.  The  pattern  is  loosened  by  the 
vibrator  frame  when  the  cope  is  ready  to  be  lifted. 

Fig.  62  shows  a  multiple  mold  made  by  the  use  of  a 
press  molding  machine  and  the  casting  that  is  obtained 


122  FOUNDRY  PRACTICE 

from  the  mold.  This  secures  the  making  of  a  great  num- 
ber of  molds  on  a  small  floor  space. 

The  third  class  of  molding  machine  performs  the  op- 
eration of  ramming  and  drawing  the  pattern.  Fig.  63 
shows  such  a  machine  for  making  ells,  as  shown  at  the 
bottom  of  the  figure.  The  presser  head  conforms  to  the 
pattern,  leaving  the  cope  as  shown  after  the  sand  has  been 
compressed.  Before  compressing  the  sand  into  the  flask, 
the  sand  frame  is  placed  upon  the  flask  and  filled  to  its 
top.  The  degree  of  hardness  due  to  the  press  is  de- 
pendent upon  the  depth  of  this  sand  frame.  After  strik- 
ing off  and  venting,  the  flask  is  lifted  off  from  the  pattern 
by  the  lift  lever,  thus  mechanically  drawing  the  pattern. 
The  pattern  board  forms  the  stripping  plate. 

These  machines  are  made  for  many  special  patterns 
and  are  claimed  to  give  good  results;  and  they  very  much 
reduce  the  cost  of  making  the  mold. 


CHAPTER  IV 

CORES,  CORE  BOXES,  CORE  MACHINES,  AND  DRYING 
OVENS 

Cores  are  bodies  of  sand  in  the  mold  for  forming  in- 
terior openings  or  holes  in  the  casting.  They  may  be 
made  of  green  sand,  dry  sand,  or  loam.  Some  patterns 
are  of  such  form  that  the  core  is  formed  by  the  pattern. 
Generally  the  core  is  made  separate  from  the  mold  and 
placed  into  it.  When  made  in  green  sand  it  maintains 
the  shape  more  accurately  than  dry  sand,  as  the  core  is 
often  distorted  in  drying.  It  requires  more  skill  and  time 
to  form  green  sand  cores  than  dry  sand,  hence  the  dry 
sand  is  used  when  the  core  is  not  simple  or  easily  made  in 
green  sand. 

Dry  sand  cores  may  be  made  in  a  great  variety  of 
shapes  to  suit  any  case.  They  are  made  strong  enough 
to  resist  the  pressure  of  the  metal,  and  may  be  anchored 
so  as  to  be  almost  surrounded  by  metal,  leaving  an  opening 
through  which  the  gases  escape.  The  use  of  cores  greatly 
simplifies  molding  in  many  cases.  They  may  be  used  to 
stop  off  portions  of  the  pattern,  to  prevent  the  necessity 
of  many  parts  to  the  flask,  to  form  irregularities  and 
pockets  that  would  be  difficult  to  make  with  the  pattern, 
and  to  form  parts  of  molds  instead  of  using  a  pattern,  as 
in  pit  molding. 

123 


124  FOUNDRY  PRACTICE 

A  dry  sand  core  is  any  form  made  in  sand  mixtures, 
dried  until  hard  to  allow  handling,  and  used  to  form  part 
of  a  mold.  These  cores  may  be  made  in  any  form  from 
the  plain  to  the  very  intricate  and  irregular  cores  required 
in  some  castings.  When  properly  dried,  the  core  be- 
comes hard  so  it  may  be  handled,  and  may  be  anchored 
by  use  of  chaplets  when  necessary.  The  binder  used  in 
the  mixture  holds  the  sand  together  so  that  shapes  may 
be  easily  made  which  would  be'  very  difficult  to  form  in 
green  sand.  Dry  sand  cores  may  be  made  strong  enough 
to  support  the  sand  of  portions  of  a  mold  or  to  resist  great 
pressures  from  the  metal. 

The  proper  venting  of  cores  is  a  necessity.  All  core 
mixtures  have  a  binder  which  holds  the  sand  together 
when  dried.  This  binder  burns  out  when  in  contact  with 
the  molten  iron,  giving  off  gases  which  greatly  increases 
that  in  the  new  sand  used  in  the  core.  This  formation 
of  gas  must  have  free  relief  within  the  core  to  prevent  its 
forcing  its  escape  through  the  metal.  All  mixtures  for 
cores  must  be  sufficiently  open  to  give  free  passage  for 
the  gases. 

Cores  having  metal  against  one  face  only  will  not  re- 
quire any  special  vents.  Small  round  cores  require  a 
vent  through  the  centre.  This  should  extend  throughout 
its  length.  Cores  having  one  face  not  covered  by  the 
metal  may  be  vented  to  this  face  by  a  vent  wire  to  give 
the  necessary  relief  to  the  gases. 

When  the  core  is  large  or  not  easily  vented,  coke, 
cinders,  stones,  or  any  very  open  material  is  placed  in 
the  core  to  collect  the  gases,  which  are  led  off  by  an  open- 
ing to  the  outside.  Straight  cores  may  be  vented  by  rods 


CORES,  MACHINES,  AND  DRYING  OVENS  125 

placed  in  the  box  when  ramming  the  core.  Crooked  cores 
are  vented  by  many  methods.  When  large  enough  to  use 
coke  without  weakening  the  core,  the  vent  may  be  led 
out  by  placing  coke  through  the  centre  of  the  crooked 
part  to  lead  to  the  vent  opening.  Small  crooked  cores 
may  be  vented  in  many  ways.  A  roll  of  paraffine  laid 
through  the  core  when  rammed  will  melt  and  run  out 
when  the  core  is  dried,  giving  the  desired  vent.  Straight 
vents  may  be  made  to  the  bent  portion  of  a  core,  and  after 
drying  these  are  connected  by  cutting  away  the  core  and 
laying  in  a  string  through  one  vent  and  extending  into 
the  other,  then  covering  with  new  molding  sand  or  core 
mixture  to  re-form  the  shape.  The  desired  vent  is  left 
when  the  string  is  drawn  out. 

Core  sand t will  admit  of  hard  ramming  without  caus- 
ing trouble  when  used.  When  rammed  hard,  the  core 
will  be  stronger.  The  only  precaution  is  to  have  the  sand 
left  sufficiently  open  to  give  free  vent.  All  ramming  must 
be  done  with  the  pein  rammer  until  the  last  surface  is 
reached,  when  it  is  butted  off.  If  the  butt  is  used  be- 
tween the  layers  while  Ming  a  box,  the  surface  made  will 
not  unite  with  the  sand  rammed  on  top,  which  makes  a 
weak  place  in  the  core.  If  the  sand  is  too  wet,  it  should 
not  be  rammed  so  hard,  for  the  pores  close  easier  and 
form  a  solid  cake,  which  will  blow  when  used  in  the  mold. 

Cores  may  be  greatly  strengthened  by  putting  wires 
and  rods  into  them.  The  sand  adheres  to  the  rods  so 
closely  that  it  cannot  be  pulled  out  even  from  a  short 
core.  This  strengthens  the  core  far  more  than  the  sim- 
ple bending  of  the  rod,  because  it  causes  a  tension  in  the 
rod,  due  to  a  tendency  to  elongate  in  an  arc  of  a  circle 


126  FOUNDRY  PRACTICE 

whose  centre  is  at  the  surface  of  the  core.  This  action 
is  effective  only  to  the  amount  necessary  to  crush  the  core 
at  that  centre.  Small  cores  needing  but  little  strength 
do  not  require  rods.  The  strength  due  to  the  dry  sand  is 
sufficient  where  there  is  not  much  pressure  or  weight  to 
be  borne. 

The  rods  necessary  for  a  core  depend  upon  the  weight 
of  the  core  and  the  strength  it  must  have.  Many  cores 
are  of  such  size  or  shape  that  they  would  not  bear  their 
own  weight  without  rodding.  Small  and  thin  cores  may 
be  sufficiently  rodded  by  heavy  wire.  All  oil  cores,  except 
very  small  ones,  should  have  rods  to  hold  them  to  shape 
while  green  and  to  give  extra  strength  when  dried.  The 
oil  will  adhere  to  the  rod  so  that  it  becomes  so  firmly 
fixed  that  the  core  will  break  a  wire  before  loosening  from 
it.  Larger  cores  are  rodded  in  all  directions  so  as  to  tie 
the  whole  together  firmly.  The  rods  are  bent  to  conform 
to  the  desired  shape. 

Many  cores  require  to  be  hung  in  the  cope.  These 
must  have  hooks  or  loops  in  them  for  their  support. 
Other  cores  require  the  loop  for  handling  or  setting  them 
into  the  mold.  The  loop  is  made  of  wire  or  rods  of  the 
necessary  strength  and  is  placed  in  the  desired  position  in 
the  core.  Except  when  the  core  is  small,  the  loop  is  an- 
chored in  the  core  by  cross  rods  so  placed  as  to  brace  the 
entire  core  from  the  loop.  This  gives  strength  to  the  core 
and  makes  the  loop  capable  of  bearing  the  weight. 

Large,  heavy  cores  cannot  be  safely  rodded  by  loose, 
separate  rods,  as  they  do  not  give  sufficient  strength. 
Special  anchors,  bars,  or  core  irons  are  used  in  these 
cases.  These  core  irons  may  be  of  cast  iron,  of  wrought 


CORES,  MACHINES,  AND  DRYING  OVENS  127 

iron  welded  together,  or  may  have  cast-iron  bodies  with 
wrought-iron  parts.  These  are  so  shaped  as  to  carry  the 
entire  core  firmly  from  the  core  iron.  The  hooks  or  nuts 
for  screw  eyes  are  made  solid  to  the  core  iron  for  hand- 
ling. When  the  core  has  a  large  body  part,  loose  bars 
and  rods  are  used  to  bind  the  whole  to  the  core  iron.  In 
many  cases  the  iron  in  it  weighs  more  than  the  sand. 

Many  cores  are  made  in  two  or  more  parts  and  are 
pasted  together  after  drying.  This  is  done  in  order  to 
give  a  form  to  the  core  that  will  hold  its  shape  before 
drying.  Large  round  cores  will  sag  and  deform  while 
green  if  made  full,  supported  on  a  side.  When  made  in 
halves  the  support  comes  upon  the  flat  side,  giving  suf- 
ficient strength  to  maintain  its  shape.  The  making  of 
cores  in  halves  greatly  simplifies  the  boxes  used  and  gives 
the  largest  face  outward  to  work  from  in  making  the  core. 

The  halves  are  pasted  together  after  drying,  to  form 
the  complete  core.  The  paste  used  must  be  sufficiently 
strong  to  hold  the  core  when  handled,  when  set  in  the 
mold,  and  when  the  mold  'is  poured.  Wheat  or  rye  flour 
wet  with  water  to  an  even  mixture  forms  a  strong  paste 
for  this  purpose.  Graham  flour,  buckwheat  flour,  and 
fine  meal  each  makes  a  paste  that  may  be  smoother  but 
not  so  strong  as  wheat  flour. 

In  pasting  a  core  the  halves  must  come  to  a  close  bear- 
ing all  over  the  surface  of  the  joint.  When  the  joint 
surface  is  warped  or  irregular,  the  halves  may  be  rubbed 
together  until  a  good  bearing  is  obtained.  When  large 
or  very  irregular,  the  high  places  may  be  filed  off  or 
rubbed  down  with  a  brick.  In  some  cases  the  halves  are 
slightly  thick,  causing  the  core  to  be  elliptical  when  pasted. 


128  FOUNDRY  PRACTICE 

Therefore  a  core  should  be  measured  with  a  caliper,  and 
when  too  thick  the  joint  should  be  rubbed  down  until 
the  proper  thickness  is  obtained. 

The  sand  and  dust  on  the  joint  must  be  brushed  off 
before  putting  on  the  paste,  as  the  dust  takes  up  the  paste 
and  prevents  the  solid  joint  desired.  The  paste  should 
be  spread  over  the  portion  forming  the  joint;  the  core  is 
then  put  together  and  rubbed  slightly,  with  pressure  to 
give  close  union  to  the  parts. 

In  pasted  cores,  the  vent  is  taken  off  at  the  joint  by 
cutting  gutters  in  the  joint  surface  and  leading  off  through 
the  print  portion.  These  gutters  must  be  kept  open 
when  the  core  is  pasted.  Sometimes  it  is  advisable  to 
lay  into  the  gutter  a  rod,  a  string,  or  anything  that  may 
be  drawn  out  after  pasting. 

The  paste  must  be  dried  in  order  to  give  it  strength. 
If  pasted  while  hot,  the  core  will  dry  the  paste.  When 
pasted  cold,  the  core  should  be  put  in  the  oven  until 
dried. 

If  the  core  is  properly  pasted  and  dried,  the  joint  will 
be  as  strong  as  any  part  of  the  core  outside  of  the  rods  or 
anchors. 

All  cores  are  baked  or  dried  to  drive  off  the  moisture 
and  harden  the  core.  If  a  core  is  heated  too  much  or 
left  in  the  oven  after  it  is  dry,  the  binder  burns  out,  leav- 
ing the  soft  burnt  sand  which  crumbles  and  cannot  be 
used.  When  a  core  is  dry  it  will  give  a  clear  ring  when 
tapped  with  a  stick  or  hammer.  A  conven  ent  tool  for 
sounding  a  core  is  the  handle  of  a  trowel.  If  the  core  is 
only  partly  dry  the  ring  will  be  deadened. 

Cores  may  also  be  tested  for  dryness  by  the  odor. 


CORES,  MACHINES,  AND  DRYING  OVENS  129 

When  green  the  flour,  or  binder,  gives  an  odor  similar  to 
sour  dough.  When  dry,  no  steam  nor  odor  of  green 
binder  can  be  detected. 

The  ovens  for  drying  cores  are  of  various  kinds,  chiefly 
using  direct  heat,  although  some  have  indirect  heat.  The 
indirect  heat  process  is  where  the  fire  is  in  a  separate 
chamber  about  the  oven  where  the  cores  are  dried.  The 
direct  heat  process  is  to  have  the  fire  so  placed  that  the 
heat  and  smoke  pass  directly  through  the  oven  into  the 
chimney. 

By  indirect  heating,  the  intensity  of  the  heat  is  more 
nearly  even  throughout  the  oven.  By  direct,  the  upper 
part  is  always  much  hotter  than  the  lower  part.  By  direct 
heating,  the  chimney  flue  opens  from  the  lower  part  of 
the  oven  at  the  end  opposite  the  fire.  This  draws  the 
cooler  air  from  the  bottom,  which  must  be  replaced  by 
the  hotter  air  from  the  upper  part  or  from  the  fire;  thus 
it  distributes  the  heat  more  evenly  and  reduces  the  loss 
of  heat  passing  into  the  chimney. 

The  ovens  for  small  cores  are  fitted  with  shelves,  upon 
which  the  plates  of  cores  may  be  placed.  These  are  so 
arranged  as  to  be  convenient  and  accessible  while  the 
oven  is  hot.  A  convenient  form  of  oven  for  small  cores  is 
shown  in  Fig.  64.  In  this  oven  the  shelves  are  of  the 
form  of  a  semicircle  hung  at  its  centre.  A  door  is  fitted 
to  each  side,  thus  closing  the  oven  when  the  shelf  is 
swung  out  or  in. 

The  common  forms  of  core  ovens  have  the  shelves 
fixed  within  the  oven.  The  cores  are  placed  upon  the 
shelves  through  a  door  that  opens  in  front  of  the  shelves, 
or  the  oven  is  so  arranged  that  the  coremaker  may  go 


I30 


FOUNDRY  PRACTICE 


inside  the  oven  to  the  shelves  arranged  about  in  it.     The 
ovens  have  the  coke  fire  at  one  end  while  the  gases  are 


FIG.  64. 

drawn  off  near  the  bottom  at  the  opposite  end.  This 
arrangement  distributes  the  heat  as  evenly  as  possible, 
but  great  variation  is  noted  at  various  points  of  the  oven. 
The  shelves  at  the  top  nearest  the  fire  are  very  hot,  while 


CORES,  MACHINES,  AND  DRYING  OVENS  131 

the  ones  that  are  low  at  the  opposite  end  are  not  hot 
enough  to  dry  a  core.     This  distribution  of  heat  is  often 


FIG.  65. 

of  advantage,  as  those  cores  which  must  be  dried  quickly 
or  slightly  burned,  as  oil  cores,  may  be  placed  on  the 


O 


FIG.  66. 


hottest  shelves,  while  other  cores  may  be  best  dried  in 
cooler  portions  of  the  oven.     Cores  that  are  replaced 


132  FOUNDRY  PRACTICE 

in  the  oven  for  drying  the  blacking  or  the  paste  may  best 
be  placed  in  the  coolest  parts  of  the  oven. 

Fig.  65  shows  an  elevation  and  a  sectional  view  of  an 
oven  for  small  cores.    Fig.  66  gives  detail  of  the  same, 


FIG.  67. 

showing  its  operation.  The  shelves  for  the  cores  are 
mounted  on  wheels  at  the  back  and  are  carried  at  the 
front  by  the  trolley,  while  the  shelf  is  drawn  out.  Each 
shelf  has  its  door  at  front  and  at  back,  so  that  the  oven  is 
closed  when  the  shelf  is  out  or  in.  Any  one  may  be 


CORES,  MACHINES,  AND  DRYING  OVENS 


drawn  out  by  hooking  the  trolley  to  the  handle,  as  in  the 
case  of  the  one  in  Fig.  66.  The  whole  number  may  be 
drawn  at  once  if  so  desired. 

A  form  of  oven  used  extensively  in  shops  making  a 
special  line  of  castings  is  one  having  a  core-truck  with 
shelves  fitted  for  the  special  cores  used.  The  truck  is 
drawn  out  of  the  oven  while  it  is  loaded  or  unloaded,  and 
is  replaced  in  the  oven  while  drying  the  cores.  A  form 


FIG.  68. 

of  such  a  truck  is  shown  in  Fig.  67.  The  oven  for  this 
purpose  has  its  interior  dimensions  to  suit  the  size  of 
truck  and  its  front  end  is  fitted  with  some  form  of  door 
that  may  be  opened  for  removing  the  truck.  The  fire  is 
made  below  the  floor  line  at  the  back  end  of  the  oven  and 
the  gases  drawn  off  at  the  front  end  near  the  bottom  of 
the  oven.  A  simple  form  of  truck,  or  core  car,  is  shown 
in  Fig.  68.  This  is  suited  to  large  cores  of  any  form. 
It  is  of  advantage  in  jobbing  shops  having  heavy  cast- 
ings, because  the  cores  there  used  vary  greatly  in  size 


134  FOUNDRY  PRACTICE 

and  form.     These  may  be  decked  by  placing  rests  on  the 
platform  and  laying  bars  across. 

The  mixture  for  a  core  may  vary  greatly  to  suit  par- 
ticular conditions  and  different  sands.  The  amount  of 
binder  necessary  is  that  which  will  form  a  hard  core  when 
dry  and  which  will  not  be  too  close,  nor  burn  out,  allow- 
ing the  metal  to  enter  into  the  core  forming  roughness 
on  the  casting. 

The  mixture  given  in  Receipt  No.  i  is  well  adapted 
to  small  cores  made  on  the  bench.  With  some  sands 
this  percentage  may  be  increased.  With  large  cores,  the 
percentage  may  be  reduced  to  that  of  i  part  flour  to  12 
parts  sharp  sand. 

The  core  may  be  strengthened  in  heavy  work  by  mix- 
ing a  percentage  of  new  molding  sand  with  the  sharp 
sand.  The  mixture  given  in  Receipt  No.  4  gives  a 
strong  core  for  large  work,  as  arm  cores  for  fly  wheels, 
etc. 

When  a  core  is  nearly  surrounded  by  metal,  it  is  neces- 
sary to  have  a  strong  core  with  as  little  enclosed  gas  as 
possible.  Receipt  No.  2  forms  a  core  which  is  very  strong 
and  which  may  be  easily  vented  since  it  is  nearly  an  oil 
core.  This  mixture  while  green  will  not  have  much 
strength,  so  that  it  may  be  difficult  to  dry  without  its 
losing  the  form  desired.  By  adding  a  small  percentage 
of  flour,  the  green  core  has  more  strength  and  has  as 
much  strength  when  dry. 

Receipt  No.  3  will  give  a  hard  oil  core  which  has  great 
strength  for  its  size  and  will  not  blow  when  the  metal 
covers  the  greater  percentage  of  it.  This  is  of  greatest 
value  in  making  thin  split  cores.  The  core  should  be 


CORES,  MACHINES,  AND  DRYING  OVENS  135 

slightly  burned   after  drying    to  give   an  open  texture 

without  injuring  its  strength. 

The  mixture  given  in  Receipt  No.  5  is  for  making  cores 

by  the  machine.     The  proportions  may  be  varied  to  give 

the  best  core  with  the  easiest  operation  of  the  machine. 

If  the  sand  is  too  wet  or  has  too  much  flour,  it  will  stick 

to  the  tube,  thus  clogging  the  machine.     If  too  dry,  the 

machine  will  not  compress  the  sand  sufficiently  to  give  a 

strong    core.     These    cores    are    improved    by    burning 

slightly  while  drying. 

Receipt  No.  i. — 6  parts  fine  sharp  sand,  i  part  flour,  wet 
with  water.  Vary  the  above,  to  suit  conditions,  to 
12  parts  sand  to  i  part  flour. 

Receipt  No.  2. — 2  parts  fine  sharp  sand,  i  part  new  mold- 
ing sand.  To  75  parts  of  mixture  add  i  part  of  linseed 
oil  or  core  compound. 

Receipt  No.  3. — Add  oil  to  the  sharp  sand  until  it  becomes 
saturated,  or  will  show  slightly  on  the  finger-nail  when 
pressed  into  the  sand. 

Receipt  No.  4. — 3  parts  of  sharp  sand,  i  part  new  mold- 
ing sand,  i  part  flour  to  8  parts  of  the  mixture.  Wet 
with  water. 

Receipt  No.  5. — 10  parts  of  medium  grade  sharp  sand, 
i  part  flour.     To  75  parts  of  mixture  add  i  part  linseed 
oil.     Moisten  with  water  until  the  whole  adheres. 
The  face  of  the  core  which  is  to  be  covered  with  iron 

is  coated  with  blacking  to  give  a  smooth  face  and  prevent 

fusion  with  the  sand. 

The  mixtures  of  blacking  for  dry   sand  molds  give  a 

very   good   mixture  for  large   cores.     Cheaper  mixtures 

give  good  results  on  small  cores.     The  simplest  blacking 


136  FOUNDRY  PRACTICE 

is  the  prepared  coke  blacking  or  black  lead  mixed  with 
water  ot  the  desired  thickness.  A  better  mixture  for 
light  cores  may  be  made  by  use  of  the  following  receipt: 
Mix  6  parts  charcoal  blacking  and  i  part  graphite.  Wet 
with  molasses  water  or  sour  beer. 

Hay  or  straw  is  twisted  into  ropes  in  order  to  form 
an  open  band  which  may  be  placed  where  it  gives 
strength  in  holding  the  sand,  besides  providing  a  free 
escape  for  the  gases.  It  is  used  chiefly  in  loam  work, 


FIG.  69. 

or  in  cores  where  the  core  barrel  is  used.  It  is  some- 
times used  in  molds  to  provide  a  vent  passage  from  parts 
of  the  mold. 

The  rope  is  made  by  twisting  by  hand  or  by  the  use  of 
a  hay-rope  twisting  machine.  Fig.  69  shows  a  machine 
for  twisting  hay  rope  and  winding  the  rope  upon  a  reel 
for  convenience  in  handling. 

Long  round  cores  are  often  made  upon  a  core  barrel 
to  give  them  strength  and  to  lessen  the  amount  of  core 
sand  necessary  to  make  the  core.  The  barrel  is  a  pipe  of 
wrought  or  cast  iron,  having  holes  through  its  surface  to 


CORES,  MACHINES,  AND  DRYING  OVENS  137 

allow  the  free  escape  of  the  gases  from  the  outside  to  the 
inside  of  the  barrel.  When  made  of  cast  iron,  the  outer 
face  has  projections  and  unevenness  for  holding  the  core 
sand  to  the  barrel.  Wrought-iron  barrels  may  be  the 
plain  pipe  with  vent  holes  drilled  through  at  frequent  in- 
tervals. 

The  core  barrel  is  used  for  making  the  centre  core  for 
columns,  pipes,  cylinders,  and  round  cores  of  that  type. 
The  core  made  on  the  core  barrel  is  much  lighter  and 
easier  to  handle  than  a  solid  sand  core.  The  barrel  gives 
the  core  greater  strength  than  the  rods,  especially  in  cores 
of  small  diameter.  The  amount  of  core  mixture  used  to 
make  the  core  will  be  that  necessary  to  form  a  shell  over 
the  barrel,  while  the  other  core  must  be  solid.  The 
saving  of  core  mixture  is  often  worthy  of  consideration. 

In  order  to  form  a  core  on  a  core  barrel,  the  barrel  is 
wrapped  with  hay  or  straw  rope,  then  covered  with  loam 
or  core  mixture  to  give  the  desired  diameter.  The  barrel 
is  placed  upon  supports  at  each  end  and  fitted  with  a 
crank  so  that  it  may  be  rotated.  This  mechanism  with 
the  strike  o:  sweep  for  forming  the  face  of  the  core  is 
called  a  core  lathe.  The  end  supports  may  be  a  frame 
having  a  notch  in  the  upper  side  for  holding  the  barrel  or 
centre  shaft  which  supports  the  barrel.  The  frame  ex- 
tends horizontally  to  support  the  sweep.  The  barrel  is 
placed  upon  the  supports  and  rotated  by  the  crank,  while 
the  coremaker  guides  the  hay  rope  onto  it  until  the  de- 
sired length  is  covered.  The  surface  is  then  covered  with 
the  core  sand  and  compressed  to  give  the  necessary 
strength.  The  sweep  is  placed  upon  the  supports  and 
the  surface  swept  up  by  rotating  the  barrel.  The  sweep 


FOUNDRY  PRACTICE 


is  moved  toward  the  axis  until  the  desired  diameter  of 
core  is  formed,  when  the  surface  is  slicked  ready  for  dry- 
ing. 

The  procedure  in  making  cores  varies  to  quite  an  ex- 
tent in  particular  cases.  The  general  principles  always 
apply  and  the  variations  are  mainly  in  rodding,  venting, 
and  mixture  of  sand  best  suited  to  the  special  core  de- 
sired. As  it  is  impossible  to  give  examples  and  explana- 
tion to  cover  every  case,  a  few  examples  are  given  to 
illustrate  the  principal  methods  of  making  cores. 


u 


U 


FIG.  70. 

All  small  cores  that  do  not  require  rodding  are  made 
by  ramming  the  box  full  of  the  core  mixture  and  venting 
toward  the  print  side  of  the  core.  It  is  then  ready  to  put 
on  the  plate  for  drying. 

Fig.  70  shows  a  box  for  making  a  round  core.  The 
method  of  making  such  a  core  is  here  given.  The  two 
parts  of  the  box  are  clamped  together  and  placed  on  end 
upon  a  smooth  board  or  plate.  Some  core  sand  is  placed 
in  the  box,  then  the  vent  wire  is  pressed  into  the  centre. 
The  sand  is  rammed  around  the  vent  wire  with  any  con- 
venient rod.  This  form  of  core  will  stand  to  be  rammed 


CORES,  MACHINES,  AND  DRYING  OVENS  139 

quite  hard.  The  ramming  is  continued  while  the  sand 
is  added  in  small  amounts  until  the  box  is  full.  The  top 
is  slicked  even  with  the  box  and  the  vent  wire  withdrawn. 
The  box  is  inverted  and  the -lower  end  slicked  even  with 
the  box  if  it  were  not  so  left  by  the  piece  it  rested  upon. 
The  clamps  are  removed  from  the  box.  The  core  is 
loosened  by  rapping  the  box  on  the  sides. 

Half  of  the  box  is  lifted  off  from  the  core,  leaving  it  in 
the  lower  half.  This  is  turned  out  upon  the  plate  by  the 
follow  ng  method.  Place  the  part  containing  the  core  on 
the  plate.  With  the  fingers  of  both  hands  gently  resting 
on  the  core,  raise  the  box  with  the  thumbs  so  that  it  turns 
over  until  the  fingers  nearly  touch  the  plate.  Gradually 
withdraw  the  fingers,  allowing  the  core  to  slide  down  to 
the  plate  evenly  and  gently.  The  core  may  be  moved  by 
placing  a  straight  side  of  the  box  against  it  and  moving 
the  box  until  the  core  is  in  the  desired  place. 

The  object  of  placing  the  vent  wire  before  ramming 
is  to  keep  it  in  the  centre  of  the  core.  When  the  core  is 
short,  it  may  be  quicker  to  ram  the  box  full,  then  press 
the  vent  wire  through,  using  care  to  keep  it  in  the  centre. 
When  the  core  is  long  and  must  bear  a  pressure  it  should 
have  a  rod  put  in  while  ramming.  Many  core-makers 
press  the  rod  in  after  ramming  the  core  by  running  the 
vent  wire  through  first.  This  is  a  very  poor  plan,  as  the 
sand  may  be  loose  around  the  rod,  so  that  it  does  not 
strengthen  the  core,  or  it  may  close  the  vent,  causing 
trouble  in  that  way.  In  order  that  a  rod  should  strengthen 
a  core,  it  must  be  solid  into  the  sand  as  a  part  of  it. 

Many  cores  are  made  in  a  skeleton  box  with  a  strike 
or  former.  This  form  of  box  is  very  cheap  to  make  and 


140 


FOUNDRY  PRACTICE 


a  core  may  be  readily  made  in  it.     Fig.  71  shows  such  a 
box  with  its  strike.     This  makes  one-half  of  the  core, 


FIG.  71. 

which  when  pasted  forms  the  core  shown  in  Fig.   72. 
This  core  is  18  in.  in  diameter  at  the  base,  4  in.  at  the 


FIG.  72. 

top,  and  30  in.  long.  The  core  rests  on  prints  at  each 
end,  and  must  be  sufficiently  strong  at  the  small  end  to 
sustain  the  weight  of  the  core  when  placed  in  the  mold. 


CORES,  MACHINES,  AND  DRYING  OVENS  141 

The  box  is  placed  upon  a  plate  having  a  smooth  face. 
A  little  dry  sand  is  sprinkled  over  the  plate  to  prevent  the 
core  from  sticking  to  it.  Core  sand  is  then  filled  in  to  a 
depth  of  about  two  inches.  A  rod  about  26  inches  long  is 
wet  with  paste  and  placed  in  the  centre  of  the  box  and 
bedded  into  the  sand.  Sand  is  then  filled  in  and  rammed 
with  the  pein  until  it  is  nearly  of  the  required  size.  The 
last  sand  is  butted  onto  the  surface,  making  a  solid  core 
to  strike  off.  A  few  vents  are  directed  to  the  centre  of 
the  lower  side  from  the  larger  portions  of  the  core. 

The  face  of  the  core  is  struck  off  by  maintaining  the 
notch  A  against  the  end  of  the  box  and  always  keeping 
the  face  of  the  strike  directed  radially  to  the  centre  line 
of  the  core.  The  surface  is  slicked  and  brought  to  an 
even  smooth  surface.  The  box  is  then  drawn  from  the 
core. 

The  second  half  is  made  in  the  same  manner.  The 
two  halves  are  blackened  with  a  medium  thick  mixture 
of  the  blacking  and  are  put  in  the  oven  and  dried.  They 
are  then  placed  together  and  rubbed  to  give  a  good  bear- 
ing. The  two  ends  should  be  tried  with  a  caliper  for  the 
correct  diameter.  When  too  large,  the  core  should  be 
rubbed  down  until  the  proper  diameter  is  reached.  The 
halves  are  then  taken  apart  and  the  vent  gutter  is  cut 
through  the  centre  the  full  length  of  the  core  and  on  both 
halves.  This  should  connect  the  vents  previously  made 
through  the  body  of  the  green  core.  The  sand  and  dust 
are  removed  from  the  face  of  the  joint  and  paste  is  put 
upon  one-half  of  the  core.  The  paste  should  be  strung 
along  in  a  thick,  narrow  row  midway  between  the  edge 
and  the  vent  gutter.  If  spread  thin  over  the  surface  it 


142  FOUNDRY  PRACTICE 

may  not  give  contact  at  a  portion  of  the  face.  When  put 
on  thick,  it  squeezes  out  when  the  core  is  put  together  and 
makes  a  firm  joint.  Care  must  be  taken  to  prevent 
filling  the  vent  gutter  with  paste  when  the  core  is  put 
together,  thus  closing  the  vent  passage. 

The  half  without  the  paste  is  then  placed  upon  the 
other  and  the  two  pressed  together  with  a  little  rubbing 
to  force  the  excess  of  paste  out  of  the  joint.  The  open- 
ings still  left  at  the  joint  on  the  sides  of  the  core  should 
be  filled  with  stiff  blacking  if  small,  but  when  large  pieces 
may  have  broken  off,  the  interior  surface  is  covered  with 
paste  and  core  mixture  is  pressed  in  to  fill  to  the  desired 
surface.  The  face  of  the  joint  may  be  smoothed  by 
going  over  with  wet  blacking  on  a  swab  or  brush.  After 
the  paste  and  blacking  are  dried,  the  core  is  ready  for 
use  in  the  mold. 

The  skeleton  box  and  strike  may  be  made  use  of  under 
greatly  varying  conditions.  Whenever  there  is  a  core  or 
portion  of  a  core  that  may  be  struck  into  the  desired  form 
with  a  strike,  the  skeleton  box  may  be  made  use  of.  The 
most  general  use  is  found  in  making  round  cores,  espe- 
cially large  sizes.  The  strike  in  this  case  is  straight. 
The  strike  or  former  is  also  used  to  move  lengthwise  of 
the  core  instead  of  crosswise  or  around  the  core.  In 
making  cores  for  water-pipe  specials,  as  ells,  tees,  etc., 
a  former  is  made  of  the  desired  semicircumference,  and 
the  core  is  shaped  by  guiding  upon  the  skeleton  box  or 
upon  a  core  plate  made  to  the  desired  outline. 

The  head  stock  core,  shown  in  Fig.  24,  is  made  in  a 
half  box,  having  loose  pieces  to  form  the  recesses  for  the 
bearings.  The  halves  are  made  the  opposite  way  by 


CORES,  MACHINES,  AND  DRYING  OVENS  143 

having  reversible  parts  to  the  one  box  or  by  having  two 
separate  boxes.  The  preferable  way  is  to  have  the  one 
frame  with  the  loose  piece  to  make  the  desired  parts. 
This  core  is  thick  enough  to  have  the  necessary  strength 
without  rodding.  The  box  is  filled  about  four  inches  with 
core  sand  and  rammed  with  a  small  pein  rammer.  The 
loose  pieces  are  put  in  place  and  the  core  sand  is  bedded 
under  and  around  them,  care  being  used  to  ram  it  suffi- 
ciently and  to  keep  the  pieces  in  their  proper  position. 
The  remainder  of  the  box  is  filled,  rammed,  and  butted 
off.  The  face  is  struck  off  and  surfaced  with  the  trowel 
even  with  the  top  of  the  box.  Vent  gutters  are  cut  to 
lead  off  at  the  print  side.  Slant  vents  are  directed  from 
the  gutter  under  the  loose  pieces  and  into  the  body  por- 
tions of  the  core.  The  loose  pieces  are  then  drawn  from 
the  box.  The  face  is  slicked,  if  necessary,  then  the  open- 
ing is  filled  with  molding  sand  of  the  usual  temper  for 
molding.  This  supports  the  overhanging  portion  of  the 
core  while  it  is  green  and  is  easily  removed  when  dry. 

A  core  plate  is  placed  on  the  box  and  the  box  is  turned 
over,  holding  the  two  firmly  together.  The  box  is  rapped 
on  all  sides,  then  drawn  vertically  with  light  rapping  on 
the  outside  of  the  box.  The  core  is  slicked,  then  damp- 
ened on  the  face  with  water  and  placed  in  the  oven  for 
drying.  The  face  of  the  core  is  dampened  to  form  a 
harder  skin  when  the  core  is  dried.  If  too  much  water 
is  put  on  at  any  spot,  it  washes  away  the  binder,  leaving 
the  face  soft  and  rough  with  loose  sand.  The  water  may 
best  be  sprinkled  on  the  core  by  wetting  a  brush  and 
throwing  the  water  from  it  by  holding  the  hand  and 
striking  the  brush  against  it  with  the  other,  so  that  the  jar 


144 


FOUNDRY  PRACTICE 


throws  the  water.  With  a  little  practice  the  core  may  be 
dampened  just  as  desired  by  this  method.  A  more  con- 
venient method  of  dampening  the  core  is  by  use  of  the 
spray  can  or  spraying  bellows. 

The  core  is  blackened,  pasted,  and  finished  as  in  the 
previous  case,  giving  the  completed  core  desired. 

A  simple  form  of  core  using  a  special  anchor  may 
be  found  in  making  a  large  round  core  for  a  cylinder. 
Fig.  73  shows  an  anchor  for  half  of  a  core  for  a  cylinder 


L 

Jl 

© 

][ 

: 
i 

© 

r 

FIG.  73. 

48  in.  in  diameter.    The  anchor  was  made  for  a  skeleton 
box. 

The  method  of  making  the  core  may  be  explained 
briefly  as  follows:  The  box  is  placed  upon  a  smooth, 
even  plate  easily  accessible  to  the  drying  oven.  The 
core  sand  is  riddled  evenly  over  the  surface  enclosed  by 
the  box  to  a  thickness  of  about  one  inch.  The  anchor  is 
coated  with  flour  paste  or  clay  wash  and  placed  in  posi- 
tion within  the  box.  When  the  anchor  is  light  it  should 
be  rapped  down,  then  tucked  all  around  to  ensure  an  even, 
hard  core  under  the  anchor.  The  core  sand  is  filled  in 
and  peined  firmly.  Each  layer  should  be  but  3  or  4  in. 
in  thickness.  After  the  anchor  is  covered  to  a  thickness 


CORES,  MACHINES,  AND  DRYING  OVENS  145 

of  about  2  in.,  the  core  is  vented,  leading  toward  the 
centre.  A  bed  of  coke  is  laid  through  the  centre  about 
10  in.  wide  and  5  in.  deep.  .  Long  rods  are  laid  in  near 
the  wrought-iron  bands  to  firmly  tie  the  sand  between 
them.  Rods  are  placed  at  the  outer  rim  at  intervals  of 
2  or  3  in.  as  the  core  is  rammed.  This  size  of  core  must 
be  very  solid  in  order  to  have  sufficient  strength  to  carry 
its  own  weight. 

While  ramming,  it  saves  time  to  fasten  pieces  onto  the 
outside  of  the  frame  of  the  box  to  hold  the  core  to  the 
desired  form.  Without  the  pieces  on  the  sides,  the  sand 
will  crush  out  or  expand  at  the  bottom  while  ramming  on 
the  upper  portion  of  the  core.  When  the  ramming  is 
completed,  the  pieces  are  taken  off  the  side  and  the  entire 
core  is  vented  to  the  coke  centre.  It  is  then  struck  off 
and  the  surface  slicked  to  a  smooth,  even  face.  This 
anchor  is  provided  with  nuts  into  which  screw  eyes  are 
placed  for  handling  the  core.  The  screw  eyes  are  left  in 
while  ramming  the  core.  The  rods  must  be  kept  at  least 
an  inch  from  the  screw  eye,  so  that  they  will  not  be 
loosened  when  the  screw  eye  is  removed. 

The  box  may  be  taken  from  the  core  and  the  remainder 
of  the  core  is  slicked.  Wet  blacking  is  put  evenly  over 
the  surface.  The  blacking  should  be  as  thick  as  will 
spread  readily  and  evenly.  The  core  is  then  ready  to 
dry. 

The  other  half  has  the  nuts  in  the  anchor  offset  from 
those  in  the  first  half,  so  that  openings  may  be  left  through 
the  entire  half  directly  over  the  nuts  in  the  previous  one. 
When  the  core  is  together  finished,  the  screw  eyes  are 
fastened  into  the  lower  half  of  the  core.  The  second  half 


146  FOUNDRY  PRACTICE 

is  made  the  same  as  the  first,  except  that  round  sticks 
are  placed  exactly  in  the  position  of  the  nuts  of  the 
first  half. 

The  core  should  be  pasted  while  one-half  is  hot  in 
order  to  dry  the  paste.  The  crack  at  the  parting  is  filled 
with  hard  blacking  or  core  sand,  then  coated  with  black- 
ing and  dried  by  replacing  in  the  oven  or  by  a  fire  built 
around  the  core. 

The  same  core  may  be  made  in  many  other  ways,  de- 
pendent upon  the  appliances  available.  The  principles 
are  similar  in  making  all  cores  having  special  anchors. 
All  large  cores  must  have  special  frames  or  anchors  to 
give  them  strength.  The  forms  of  these  anchors  and  the 
fitting  for  handling  are  nearly  as  various  as  the  different 
cores  in  which  they  are  used. 

In  many  cases  the  core  is  nearly  submerged  in  iron 
when  the  mold  is  poured.  These  cores  must  be  made 
so  as  to  give  very  free  vent  to  the  gases  in  order  to  prevent 
blowing  in  some  part.  Where  the  core  is  large  enough 
to  easily  collect  the  gases  at  its  centre  and  lead  them  off 
through  the  print,  the  core  may  be  made  very  similar  to 
other  cores.  When  the  core  is  thin  or  so  shaped  that 
proper  venting  is  difficult  to  obtain,  the  mixture  should 
be  such  as  to  give  a  hard  core  with  as  little  gas  as  pos- 
sible. 

The  core  shown  in  Fig.  74  is  for  forming  a  pocket  in  a 
crank  disk  which  will  be  filled  with  lead  as  the  counter- 
weight for  balancing  the  engine.  The  core  here  shown 
is  a  semicircular  segment  whose  inner  radius  is  10  in. 
and  outer  radius  2iJ  inches.  The  thickness  is  3  in.  with 
four  openings  on  one  side  2j  in.  in  diameter.  This  core 


CORES,  MACHINES,  AND  DRYING  OVENS  147 


is  surrounded   by  metal,  except  the   openings   through 
which  the  vent  is  led  off. 

To  make  this  core,  the  mixture  given  in  Receipt  No.  2 
proved  very  satisfactory.  Procure  four  pieces  of  wrought- 
iron  pipe  i  in.  or  ij  in.  in  diameter  and  4  in.  long. 
Burr  out  one  end  so  that  the  pipe  bulges  bell-shaped. 
Cover  the  pipe  well  with  linseed  oil,  then  place  in  the 
centre  of  each  print  or  opening  and  fill  in  with  the  core 
sand.  This  pipe  extends  to  the  centre  of  the  core  where 
the  gases  are  led  off.  The  entire  box  is  filled  in  a  little 
o\er  an  inch  in  depth  with  the  core  sand  and  rammed. 


FIG.  74. 

Wires  are  laid  in  to  bind  the  core.  These  wires  should 
be  of  such  a  size  as  to  hold  the  core  and  still  be  easy  to 
remove  from  the  casting  through  these  small  openings 
of  2j  in.  in  diameter.  These  wires  are  laid  in  lengthwise 
of  the  core,  placing  one  near  the  outer  circle  and  one  near 
the  inner,  while  one  is  placed  about  an  inch  away  from 
the  pipes  on  either  side  of  it.  The  wires  are  bedded 
into  the  sand  now  in  the  box.  Sand  is  filled  in  to  the 
level  of  the  top  of  the  vent  pipe. 

Vent  gutters  are  laid  out  just  inside  of  the  outer  wires, 
with  a  similar  one  through  the  centre  to  connect  the  vent 
pipes.  Cross  gutters  connect  the  ends  and  join  the  outer 


148  FOUNDRY  PRACTICE 

gutter  at  each  of  the  pipes,  and  similarly  midway  between 
the  vent  pipes.  These  gutters  are  made  to  a  depth  of 
about  J  inch  below  the  centre.  Fine  coke  is  laid  in  the 
gutter  to  a  depth  of  about  i  inch.  The  coke  taken  is 
that  which  will  pass  through  a  No.  2  riddle  and  will  not 
pass  through  a  No.  6.  The  coke  is  then  covered  with 
coarse  sharp  sand  or  fine  gravel  to  prevent  the  core  sand 
filling  up  the  openings  between  the  coke.  This  should 
bring  the  sand  above  the  top  of  the  pipes.  The  pipes 
should  be  filled  with  waste  or  anything  to  prevent  the 
sand  from  filling  them,  and  the  waste  may  be  removed 
after  the  core  is  finished.  The  top  of  the  pipes  is  cov- 
ered with  coke  to  connect  freely  with  the  vent  gutters. 
This  is  covered  with  sand  the  same  as  the  gutters.  Core 
sand  is  filled  in  to  the  top  of  the  gutters  and  rammed. 
Cross  wires  are  laid  at  distances  of  about  4  or  5  inches  to 
bind  the  core  together.  A  little  more  sand  is  filled  in 
over  the  entire  surface  of  the  box  and  long  rods  laid  in  as 
before.  The  remainder  of  the  box  is  filled  and  rammed. 
The  top  is  struck  off  even  with  the  box  and  the  face 
slicked  smooth  with  the  trowel.  Parting  sand  or  dry 
sharp  sand  is  dusted  over  the  face  to  prevent  its  sticking 
to  the  plate.  A  straight  plate  is  clamped  onto  the  core 
box  and  turned  over,  when  the  box  may  be  removed 
giving  the  core  as  desired. 

Oil  or  core  compound  readily  bakes  onto  a  plate  so  as 
to  stick  the  core  to  it.  When  making  these  cores,  some- 
thing must  be  put  onto  the  plates  to  prevent  the  oil  from 
fastening  to  the  plates.  Other  cores  separate  readily 
from  the  plates  after  drying. 

The  round  cores  of  various  sizes  are  used  in  so  many 


CORES,  MACHINES,  AND  DRYING  OVENS  149 


150  FOUNDRY  PRACTICE 

different  castings  that  all  foundries  keep  a  supply  of  each 
size  in  stock.  These  may  be  cut  to  the  length  desired  in 
any  case.  This  is  a  much  cheaper  method  than  making 
special  cores  for  each  pattern  used.  The  boxes  for  cores 
up  to  4  in.  in  diameter  are  made  similarly  to  those  shown 
in  Fig.  70,  and  of  a  standard  length. 

Machines  have  been  invented  for  making  these  stock 
cores  which  greatly  reduces  the  cost  of  labor.  These 
machines  are  made  with  changeable  parts  for  making 
cores  up  to  about  3  in.  in  diameter.  There  are  several 
manufactories  making  machines  for  this  purpose.  The 
hammer  core  machine  shown  in  Fig.  75  is  fitted  to  make 
cores  from  f  in.  to  3  in.  in  diameter.  The  mixture  is 
placed  in  the  hopper  and,  by  turning  the  cr,ank  wheel, 
is  forced  through  the  tube  of  the  desired  size  by  a  bit 
directly  back  of  the  tube.  These  give  a  core  vented  in 
the  centre  throughout  its  length  and  of  an  even  hardness. 
The  ramming  is  dependent  upon  the  friction  of  the 
sand  on  the  tube  through  which  the  core  passes. 

The  mixture  that  makes  a  very  good  core  is  one  with 
oil  and  flour  as  a  binder. 


CHAPTER  V 

CUPOLAS,  BLOWERS,  AND  MELTING  FURNACES  FOR  IRON 

THERE  are  two  types  of  furnace  most  generally  used 
for  remelting  cast  iron  in  the  foundry.  The  reverbera- 
tory  furnace  is  used  in  places  where  soft  grades  of  fuel 
are  plentiful  and  where  special  grades  of  iron  are  neces- 
sary. This  type  will  be  explained  later.  The  cupola  is 
most  generally  used  and  regarded  as  the  most  economical 
furnace. 

Fig.  76  shows  an  elevation  and  section  of  a  Newton 
cupola  which  illustrates  the  general  type  and  its  con- 
struction. The  shell  is  built  up  of  iron  or  steel  plates 
riveted  together.  This  is  lined  with  fire-brick  to  enable 
it  to  withstand  the  heat.  The  lining  is  of  the  same  diam- 
eter from  the  charging  door  to  the  bottom.  The  bottom  is 
fitted  with  doors  which  cover  the  entire  diameter  of  the 
cupola  so  as  to  allow  a  free  fall  for  the  droppings  at  the 
end  of  each  heat.  On  small  cupolas  up  to  about  30  in. 
in  diameter,  a  single  door  is  used.  In  most  cases  up  to 
72  in.  the  door  is  double,  swinging  from  the  centre  line. 
In  larger  ones  the  door  is  made  in  more  parts. 

The  tapping  hole  or  breast  is  located  above  the  bot- 
tom at  a  height  to  allow  the  sand  covering  to  be  put  upon 
the  bottom  doors  for  holding  the  molten  metal  and  for 
protecting  the  doors  from  the  heat.  The  runner  or  spout 


152 


FOUNDRY  PRACTICE 


FIG.  76. 


CUPOLAS,  BLOWERS,  AND  MELTING  FURNACES    153 

leads  from  the  breast  to  conduct  the  metal  to  the  receiv- 
ing ladle.  The  tuyeres  are  openings  through  the  lining 
for  the  air  blast  to  enter.  There  may  be  one,  two,  or 
three  rows  of  tuyeres  located  at  different  levels.  The  total 
tuyere  area  varies  from  one-tenth  the  cross-sectional  area 
of  the  cupola,  inside  the  lining,  for  small  cupolas,  to  one- 
seventh  for  those  of  large  diameter.  A  wind-belt,  or 
wind  jacket,  surrounds  the  shell  over  the  tuyeres.  The 
blast  is  conducted  to  this  wind  belt  and  enters  the  cupola 
through  the  tuyeres.  Peep  holes  are  provided  in  the 
covering  of  the  wind  jacket  opposite  each  tuyere. 
Through  these  the  melter  may  watch  the  process  of  melt- 
ing. In  the  figure  a  manometer  is  shown  fastened  to  the 
wind  jacket.  This  indicates  the  pressure  of  the  blast. 
The  amount  of  blast  pressure  varies  with  the  size  of 
cupola.  The  air  must  be  forced  to  the  centre  of  the  fire 
to  effect  combustion  there  at  the  same  rate  as  nearer  the 
lining.  In  small  cupolas  the  pressure  varies  from  4  to 
8  oz.,  while  in  larger  sizes  it  may  be  up  to  14  oz.  per 
square  inch. 

The  charging  door  is  placed  at  the  charging  floor. 
Its  height  above  the  tapping  hole  or  hearth  of  the  cupola 
should  be  such  as  to  ensure  complete  combustion  of  the 
fuel,  and  absorption  of  the  largest  percentage  of  the  heat 
by  the  charges,  before  passing  the  charging  door. 

The  hearth  is  where  the  molten  metal  accumulates, 
it  is  the  space  between  the  bottom  and  the  level  of  the 
bottom  of  the  tuyeres.  The  average  height  of  the  hearth 
is  about  10  inches. 

A  slag  notch  is  provided  on  all  cupolas  for  drawing  off 
the  slag  from  the  surface  of  the  iron  when  running  long 


154  FOUNDRY  PRACTICE 

heats.  The  slag  notch  is  fitted  similarly  to  the  breast  of 
the  cupola  but  at  a  level  slightly  below  the  bottom  of  the 
tuyeres.  It  should  be  so  arranged  that  the  tuyere  is  not 
close  on  either  side  as  the  cold  air  chills  the  slag  form- 
ing bridging,  or  obstructing  the  tuyere.  In  order  to  draw 
off  the  slag,  the  iron  is  allowed  nearly  to  fill  the  hearth 
up  to  the  slag  notch.  The  notch  is  then  opened,  allow- 
ing the  slag  to  flow  off  the  surface  of  the  iron.  When  the 
iron  appears,  the  slag  notch  is  closed  and  the  tapping  hole 
opened  to  draw  off  the  iron. 

An  alarm  tuyfere  or  plug  should  be  provided  on  every 
cupola.  When  the  metal  rises  to  the  bottom  of  the  tu- 
yeres, it  overflows  first  at  the  alarm,  thus  giving  warning 
so  the  metal  is  not  allowed  to  flow  into  the  wind  belt 
and  eventually  fill  it  with  the  iron.  A  common  form  of 
alarm  is  to  have  a  groove  through  the  lowest  tuyere 
which  allows  the  rising  metal  to  flow  off  there  first.  Di- 
rectly below  the  groove  a  plug  is  fitted  having  its  centre 
of  soft  metal  which  is  easily  melted.  The  hot  iron  or 
slag  melts  the  plug,  then  flows  to  the  outside  on  the 
ground  where  it  is  seen.  A  form  which  gives  good  results 
where  the  blast  pressure  does  not  exceed  eight  ounces  is 
to  have  a  casting  with  open  centre  and  tapered  flanges  for 
holding  its  cover  fitted  to  the  wind  jacket  below  the  alarm 
tuyere.  The  cover  has  a  small  hole  about  i  inch  in 
diameter  through  its  centre.  About  three  thicknesses  of 
common  paper  are  placed  over  the  cover,  then  slid  into 
place,  thus  making  it  nearly  air-tight,  and  burning 
through  almost  instantly  when  the  cupola  overflows. 
This  form  is  quickly  replaced,  and  acts  more  quickly 
than  most  forms  of  alarm. 


CUPOLAS,  BLOWERS,  AND  MELTING  FURNACES    155 

The  lining  of  a  cupola  is  burned  out  more  rapidly  in 
some  parts  than  in  others.  To  allow  renewing  parts  of 
the  lining  without  disturbing  the  entire  brick  work,  angle 
irons  are  riveted  to  the  shell  at  different  levels  to  hold 
the  lining  between  those  levels.  The  brick  may  then  be 
removed  between  any  two  angle  irons  without  disturbing 
the  remainder  of  the  lining. 

In  putting  a  new  lining  into  a  cupola  the  less  clay  that 
can  be  used  between  the  bricks  and  have  the  joints  sealed, 
the  longer  the  lining  will  last.  When  the  clay  is  thick 
in  the  joints,  it  burns  quickly  and  crumbles,  leaving  the 
edges  of  the  bricks  exposed  to  the  fire,  thus  burning  them 
away.  The  clay  should  be  mixed  with  water,  and  very 
thin,  so  that  by  dipping  the  bricks  into  the  mixture 
enough  will  adhere  to  form  a  tight  joint.  The  bricks 
should  be  pressed  together  to  squeeze  out  the  superfluous 
clay  and  to  ensure  a  tight  joint. 

The  shell  expands  as  the  temperature  rises,  while  the 
brick  changes  but  slightly.  To  avoid  crushing  the  lining 
when  the  shell  contracts  and  to  maintain  a  tight  lining  as 
the  shell  expands,  a  space  is  left  between  the  shell  and 
the  brick  when  the  lining  is  made.  This  space  is  rilled 
with  fine  cinders,  a  mixture  of  fire-clay  and  cinders,  or 
dry  fire-clay.  This  loose  material  protects  the  shell  from 
metal  breaking  through  the  lining,  and  allows  the  shell 
to  give  without  injuring  the  lining. 

The  cupola  must  be  prepared  for  each  succeeding 
heat.  At  the  end  of  each  heat,  when  all  the  iron  has  been 
melted,  the  bottom  is  dropped  to  allow  the  slag  and 
refuse  to  fall  out.  There  is  always  enough  molten  slag 
and  iron  left  with  the  fuel  to  form  a  solid  mass  if  allowed 


156  FOUNDRY  PRACTICE 

to  cool  in  the  cupola.  Some  of  the  refuse  always  clings 
to  the  lining  so  that  it  does  not  drop  clean.  In  some 
cases,  the  formation  on  the  lining  projects  out  for  some 
distance  or  to  nearly  cover  the  bottom.  Before  another 
heat  can  be  taken  off,  this  refuse  must  be  removed. 
This  can  be  done  with  a  Small  pick  or  pinch  bar,  having 
one  end  sharpened.  The  thick  parts  are  broken  off  with 
a  hammer,  then  the  remainder  with  the  bar.  Care 
must  be  taken  to  avoid  loosening  or  injuring  the  brick. 
Where  the  brick  is  glazed  over,  it  should  be  left,  for  that 
glazing  is  as  good  protection  to  the  brick  as  the  clay 
daubing. 

After  the  cupola  has  been  picked  out  and  the  lining 
left  clean,  a  coating  of  clay  is  put  over  the  lining.  This 
process  is  called  daubing  the  cupola  and  the  clay  mix- 
ture used  is  called  the  daubing.  The  best  clay  for  this 
purpose  is  fire-clay.  Other  mixtures  are  red  or  blue  clay 
mixed  with  sharp  sand  in  a  proportion  that  will  not  crack 
open  when  dry,  or  i  part  of  sand  to  4  of  clay.  Too  much 
sharp  sand  destroys  the  body  of  the  clay  so  that  it  crum- 
bles. The  fire-clay  is  more  expensive,  but  the  lining  will 
last  much  longer  than  when  the  mixture  is  used. 

The  daubing  is  spread  over  the  face  of  the  burned 
lining  to  a  thickness  of  from  J  to  i  inch.  Where  a  brick 
is  burned  away  deeper  than  the  others,  it  should  be  filled 
in  with  pieces  of  brick  mixed  with  the  clay.  This  keeps 
the  body  of  the  clay  thin  so  it  will  not  crack  or  sag  as  is 
the  case  when  thick  in  places.  When  the  bricks  are 
burned  away  so  that  the  lining  becomes  hollowing,  this 
should  not  be  filled  with  the  clay  to  make  it  even  with 
the  upper  parts.  If  this  is  filled  in,  the  clay  will  sag 


CUPOLAS,  BLOWERS,  AND  MELTING  FURNACES    157 

down  and  become  too  heavy  to  stick  to  the  lining.  The 
commotion  of  the  fuel  and  iron  against  it  when  melting 
soon  starts  the  clay  and  makes  it  break  away  from  the 
lining.  This  produces  a  large  amount  of  slag  and  may 
cause  trouble  by  clogging  up  the  cupola  and  stopping  the 
melting.  When  daubing  to  a  thickness  of  £  to  i  inch  will 
not  keep  the  shell  from  becoming  red  hot  during  the  heat, 
it  should  be  relined  with  brick. 

After  the  lining  is  prepared  the  bottom  is  made. 
This  consists  of  a  sand  bed  on  the  bottom  door  so  pre- 
pared as  to  hold  the  iron  and  conduct  it  to  the  tapping 
hole.  The  bottom,  or  drop,  door  is  put  up  and  perma- 
nently propped  in  place.  The  sand  is  placed  upon  it 
and  rammed  enough  to  compress  the  surface  to  bear 
the  weight  of  the  iron.  The  bottom  should  slope  back 
from  the  tapping  hole  so  as  to  give  a  free  flow  of  the 
metal  when  tapped  out.  It  should  not  be  sloped  too 
much,  as  that  gives  force  to  the  flow  which  makes  it 
difficult  to  stop,  and  if  not  sloped  enough  the  iron  may 
freeze  at  the  tapping  hole  when  the  metal  enters  it. 

The  sand  should  be  very  open  and  yet  be  loamy  enough 
to  hold  together  and  not  allow  the  metal  to  ooze  through 
it.  The  sand  may  be  taken  from  the  gangway,  or  from 
the  dirt  pile.  When  too  loamy  it  may  bake  hard  and 
form  a  crust  which  will  not  drop,  especially  in  small 
cupolas.  Very  open  sand  may  be  used,  then  after  the 
bottom  is  shaped  it  may  be  coated  with  clay  wash,  which 
forms  a  firm  crust  on  the  surface. 

Forming  the  tapping  hole  is  an  important  factor  in 
preparing  the  cupola.  The  portion  of  the  cupola  in  front 
of  the  spout  is  called  the  breast.  The  opening  made 


158  FOUNDRY  PRACTICE 

in  the  breast  for  the  metal  to  flow  through  is  called  the 
tapping  hole  or  port. 

The  brick  work  is  arched  over  the  breast,  leaving  an 
opening  for  forming  the  tapping  hole  of  the  desired 
depth.  For  the  remaining  distance  between  the  inner 
edge  of  the  tapping  hole  and  the  face  of  the  brick  the 
form  is  cone-shaped  of  such  a  pitch  that  it  enlarges 
rapidly  toward  the  inside.  The  tapping  hole  should  not 
be  more  than  three  inches  long.  The  front  may  be  put 
in  before  putting  in  the  fuel  for  the  bed,  or  afterwards  by 
using  the  fuel  for  a  backing  to  form  it  against.  When  the 
cupola  is  large  enough,  a  good  plan  is  to  place  a  board 
against  the  lining  to  cover  the  breast,  put  the  draw-plug 
in  the  desired  position  for  the  tapping  hole,  and  ram  or 
pack  the  breast  into  the  desired  shape.  The  plug  and 
board  are  removed,  then  the  inside  is  shaped  with  a  trowel 
even  with  the  brick  and  a  conical  hole  from  the  outside 
to  within  two  inches  of  the  inner  face  to  form  the  tapping 
hole.  The  breast  may  be  made  of  a  mixture  of  clay  and 
new  molding  sand  or  a  stiff  clay.  It  is  best  to  form  the 
bottom  of  clay  for  four  or  five  inches  in  front  of  the 
tapping  hole,  to  prevent  the  tapping  bar  from  making 
a  hole  in  the  bottom. 

The  spout  should  be  lined  with  clay  when  the  breast 
is  put  in.  It  is  partly  dried  with  charcoal  or  with  wood 
before  the  fuel  is  charged  into  the  cupola. 

After  the  cupola  is  prepared  for  charging,  the  kind- 
ling for  starting  the  fire  is  placed  upon  the  bottom. 
Shavings  are  placed  in  front  of  the  breast  for  lighting  and 
the  wood  on  top  of  them.  A  sufficient  amount  of  wood 
is  put  upon  the  kindling  to  ensure  its  starting  the  coke  to 


CUPOLAS,  BLOWERS,  AND  MELTING  FURNACES    159 

a  good  fire.  Coke  is  placed  upon  the  wood  to  the  amount 
of  the  bed  charge.  It  is  then  ready  to  light.  Iron  should 
not  be  charged  until  the  coke  begins  to  burn  or  until  fire 


FIG.  77. 

shows  through  at  the  top  of  the  bed.  Iron  and  coke 
should  be  charged  successively  until  it  is  at  the  height  of 
the  charging  door.  Succeeding  charges  are  put  in  as  fast 
as  the  preceding  charges  settle  away  from  the  charging 
door.  The  charge  within  the  cupola  is  kept  to  the  height 


160  FOUNDRY  PRACTICE 

of  the  charging  door  until  the  entire  amount  to  be  charged 
has  been  put  in.  This  is  so  that  the  descending  charge 
may  take  up  as  much  of  the  heat  of  the  escaping  gases 
as  possible,  so  that  the  iron  may  be  near  the  melting- 
point  when  it  descends  to  the  melting  zone.  The  charge 
of  coke  on  the  bed  must  be  of  an  amount  that  will  hold  the 
iron  at  the  melting  zone  of  the  cupola  until  it  is  all  melted. 
Each  succeeding  charge  should  be  of  the  amount  neces- 
sary to  melt  the  charge  of  iron  placed  upon  it.  The  first 
charge  of  iron  may  be  much  larger  than  the  succeeding 
charges,  but  must  not  be  so  large  that  part  of  it  passes 
below  the  melting  zone  before  it  is  melted. 

The  weights  of  the  charges  for  a  26-inch  cupola  are 
as  follows:  On  first  charge,  390  pounds  of  coke  on  bed, 
1170  pounds  of  iron.  On  each  succeeding  charge,  50 
pounds  of  coke,  alternating  with  450  pounds  of  iron. 

The  smallest  heat  that  may  be  taken  from  a  cupola 
consists  of  the  bed  charge  and  one  succeeding  charge. 
The  largest  heat  is  that  which  may  be  run  off  before  the 
tuyeres  become  clogged  so  that  the  melting  stops.  For 
long  heats,  a  flux  should  be  charged  with  the  !ron,  which 
forms  a  slag  of  the  refuse  in  the  cupola  and  makes  the 
slag  more  fluid.  The  slag  is  removed  through  the  slag 
notch,  which  clears  the  cupola,  allowing  it  to  run  longer 
without  stopping  up. 

In  order  to  produce  a  soft  iron  for  machinery  castings, 
mix  i  part  of  soft  foundry  pig  iron  with  4  parts  of  ma- 
chinery scrap  iron. 

In  using  limestone,  marble,  or  shells,  the  flux  is  charged 
with  the  iron  in  an  amount  of  30  to  50  pounds  to  one  ton 
of  iron. 


CUPOLAS,  BLOWERS,  AND  MELTING  FURNACES    161 

The  tapping  out  and  stopping  up  of  a  cupola  must 
be  accomplished  while  the  blast  is  on.  After  the  fire  is 
lighted,  the  breast,  or  port  hole  and  the  tuyeres  are 
left  open  to  supply  air  to  the  fire  until  the  blast  is 
turned  on.  The  fire  should  be  started  early  enough  to 
allow  the  wood  to  burn  out  and  the  coke  to  become  well 
ignited  before  the  blast  is  turned  on.  As  the  blast  is 
started,  the  covers  over  the  tuyeres  are  closed,  leaving 
only  the  port  hole  open.  This  is  kept  open  until  the 
molten  metal  appears,  when  it  is  closed  with  a  clay  ball. 


Bott  Stick 


Tapping-Bar 


Tapping-Chisel 

FIG.  78. 

The  blast  is  allowed  to  blow  through  the  port  so  as  to 
burn  the  coke  lodged  in  it  and  ensure  a  free  passage  for 
the  first  tap.  After  the  metal  appears  it  will  keep  the 
coke  and  refuse  out  of  the  tapping  hole.  The  fire  blow- 
ing through  the  port  heats  it  to  prevent  the  chilling  of  the 
first  iron  that  enters  it. 

The  tools  used  for  tapping  and  stopping  up  a  cupola 
are  shown  in  Fig.  78.  The  bott  stick  is  for  stopping  up 
the  cupola  by  placing  a  clay  ball  upon  the  disk  end  to 
close  the  port.  The  tapping  bar  is  used  for  tapping  out 
or  removing  the  clay  ball  which  has  become  baked  in  the 
port.  The  tapping  chisel  is  used  when  iron  or  encrusta- 


162  FOUNDRY  PRACTICE 

tions  have  frozen  about  the  tapping  hole  so  that  the  bar 
cannot  remove  them. 

In  stopping  up  the  cupola,  the  bott  stick  should  be 
directed  downward  into  the  port,  so  that  the  clay  is 
pressed  into  the  hole  before  it  dries  on  the  face  by  con- 
tact with  the  metal.  When  the  bott  stick  is  forced  against 
the  stream  of  metal,  it  washes  away  or  forms  a  crust 
which  will  not  unite  with  the  edges  of  the  hole,  therefore 
it  will  not  stop  the  flow.  The  clay  ball  must  hold  the 
pressure  of  the  blast  and  that  of  the  metal  head  acting 
against  it. 

Where  long  bott  sticks  are  necessary,  a  light  and  stiff 
one  may  be  made  of  a  tube  whose  ends  are  drawn  so 
that  a  handle  is  welded  at  one  end  and  a  rod  bearing  the 
disk  at  the  other.  A  soft  wood  bott  stick  having  a  metal 
end  on  which  to  place  the  ball  gives  good  service  and  is 
light  to  handle. 

The  clay  for  stopping  a  cupola  must  be  capable  of 
bearing  the  pressure  and  still  not  bake  so  hard  that  it  can 
not  be  broken  away  with  the  tapping  bar.  A  mixture  for 
forming  the  clay  balls  :s  i  part  sand  to  3  parts  of  good 
clay,  then  i  part  flour  to  10  parts  of  the  mixture.  This 
will  bake  as  a  core  for  holding  the  metal  and  after  drying 
it  crumbles  away  easily  before  the  tapping  bar. 

Furnaces  of  the  reverberatory  type  are  now  used 
only  where  it  is  important  to  have  the  iron  of  a  par- 
ticular quality  or  chemical  combination.  For  chilled 
work  and  castings  for  malleablizing,  the  reverberatory 
furnace  has  some  advantage  over  the  cupola.  The  fuel 
required  for  melting  a  given  amount  is  about  double  that 
of  a  cupola.  Soft  and  cheaper  fuels  may  be  used. 


UNIVERSITY 

CF 


CUPOLAS,  BLOWERS,  AND  MELTING  FURNACES    163 

In  this  furnace  the  fuel  is  burned  upon  a  grate  and 
the  metal  is  held  in  a  separate  division  where  it  is  not  in 
contact  with  the  fuel.  The  process  of  melting  is  slower, 
and  the  molten  metal  may  be  retained  in  the  furnace  until 
its  chemical  condition  is  that  desired.  Test  may  be  made 


FIG.  79. 

of  the  accumulated  metal,  and  when  the  carbon  is  in 
the  proper  condition  the  metal  may  be  tapped  out  and 
cast. 

The  two  general  forms  of  furnace  are  shown  in  Figs. 
79  and  80.  In  the  furnace  represented  by  Fig.  79,  the 
bath  is  immediately  behind  the  bridge,  while  that  shown 


164 


FOUNDRY  PRACTICE 


in  Fig.  80  has  its  bath  at  the  end  remote  from  the  bridge. 
The  fuel  is  placed  upon  the  grates  through  the  opening 
D.  The  charging  door  is  shown  at  C,  which  is  a  cast- 
iron  door  lined  with  fire-brick.  The  hearth  at  H  is  where 
the  metal  is  placed  when  charged.  P  shows  the  opening 
or  peep  holes  through  which  the  process  of  melt  ng  may 
be  seen  or  the  working  of  the  metal  effected.  The  tap- 
ping hole  is  shown  at  B  at  the  bottom  of  the  bath. 

The  bed  or  bottom  of  the  furnace  is  made  similar  to 
that  of  a  cupola,  using  the  same  mixture  or  one  that  is 


FIG.  80. 

more  open.  This  bed  will  last  for  eight  to  ten  heats,  if 
it  has  been  well  dried  before  the  first  charge  is  placed 
upon  it.  The  walls  and  roof  of  the  furnace  are  made  of 
the  most  refractory  kind  of  fire-brick,  using  care  to  have 
close  joints  and  all  crevices  carefully  sealed  to  ensure 
proper  working  of  the  furnace. 

When  iron  is  in  a  molten  state,  the  presence  of  oxy- 
gen will  affect  the  carbon  in  the  iron  and  burn  out  the 
graphitic  carbon,  making  it  harder  and  more  brittle.  The 
special  object  of  using  a  reverberatory  furnace  is  to 


CUPOLAS,  BLOWERS,  AND  MELTING  FURNACES    165 

obtain  an  iron  having  its  carbon  in  the  form  desired,  hence 
it  is  very  important  that  'cold  air  or  oxygen  should  not 
strike  upon  the  metal.  The  openings  must  be  closed 
except  when  necessary  to  assist  the  working  of  the  fur- 
nace. The  entire  charge  for  the  heat  must  be  placed 
upon  the  hearth  before  melting  begins,  because  the  fur- 
nace is  so  cooled  and  the  metal  acted  upon  by  the  cold  air 
when  a  new  charge  is  put  in  that  it  cannot  be  brought 
back  and  the  charge  melted  before  the  iron  in  the  bath  is 
too  cold  for  use.  It  is  similarly  of  importance  that  an 
even  fire  should  be  maintained  and  that  no  holes  be 
caused  by  cleaning  or  raking  the  fire,  thus  avoiding  the 
entrance  of  air  to  the  furnace  through  the  fire.  The  pres- 
sure of  the  blast  should  be  that  necessary  to  maintain  a 
rapid  fire  with  complete  combustion.  The  usual  pressure 
necessary  is  from  6  in.  to  7  inches  of  water  column. 

The  iron  should  be  charged  onto  the  hearth  so  as  to 
leave  openings  between  the  pieces.  The  first  layer  should 
extend  lengthwise  of  the  furnace  and  each  succeeding 
9ne  should  lie  across  the  preceding  layer.  The  melter 
may  often  hasten  the  process  of  melting  by  separating 
the  pieces  or  by  breaking  apart  those  that  tend  to  weld. 
The  molten  metal  is  skimmed,  as  the  accumulation  of 
dirt  or  scum  shields  the  surface  from  the  direct  action  of 
the  flames  and  thus  the  furnace  loses  its  efficiency.  When 
various  brands  of  iron  are  charged  into  the  furnace,  the 
metal  is  mixed  by  the  process  of  "boiling,"  or  " polling 
the  metal."  This  process  usually  consists  of  thrusting 
green  wood  into  the  metal,  causing  a  violent  ebullition 
throughout  the  mass,  ensuring  a  homogeneous  product. 
After  all  the  charge  is  melted  and  the  iron  is  white-hot, 


166  FOUNDRY  PRACTICE 

the  melter  dips  a  sample  from  the  furnace  with  a  small 
hand  ladle  for  testing.  If  found  satisfactory,  the  mass 
is  boiled  or  polled  for  about  five  minutes,  then  the  damper 
in  the  flue  is  closed  and  the  furnace  tapped.  The  iron 
should  then  be  poured  immediately,  as  it  will  change  in 


FIG.  81. 


the  ladles.  All  the  operations  in  the  furnace  are  con- 
ducted through  the  openings  or  peep  holes,  and  are  per- 
formed as  quickly  as  possible  to  avoid  keeping  the  holes 
open  longer  than  absolutely  necessary. 


FIG.  82. 

The  vessels  in  which  the  molten  iron  is  handled  are 
called  ladles.  They  are  generally  divided  into  four 
classes.  Hand  ladles  shown  in  Fig.  81  are  handled  by 
one  man  and  hold  up  to  50  pounds  of  iron.  The  bull 
ladles  are  those  having  a  double  shank  and  are  carried  by 
two  or  more  men.  Such  a  ladle  is  shown  in  Fig.  82 


CUPOLAS,  BLOWERS,  AND  MELTING  FURNACES    167 

with  the  bail  removed,  or,  similarly  in  Fig.  in,  having 
the  straight  shank  on  one  side.  These  ladles  hold  from 
75  t°  350  pounds  of  iron.  The  crane  ladles  are  all  those 
handled  by  use  of  the  crane.  There  are  two  general 
types,  those  having  the  fixed  shank  with  bail,  as  in  Fig. 
82,  and  those  having  the  gearing,  as  in  Fig.  83.  The 
fourth  type  of  ladle  is  used  only  in  special  places  where 


FIG.  83. 

suited  for  such  use.  These  are  mounted  on  wheels  and 
are  known  as  truck  or  car  ladles,  as  shown  in  Fig.  84. 
They  are  used  for  delivering  the  iron  from  the  cupola 
to  a  crane  ladle  or  to  the  floors  where  it  is  to  be  poured. 

The  ladle  is  made  of  sheet  iron  riveted  together,  and 
must  be  lined  with  clay  or  fire-brick  to  withstand  the 
heat.  The  clay  used  may  be  about  one  part  sharp 
sand  to  four  parts  pure  clay.  When  the  clay  itself  con- 
tains sand,  the  sharp  sand  may  be  reduced.  The  lining 


i68 


FOUNDRY  PRACTICE 


is  put  on  evenly  from  one  half  to  three  quarters  inch 
thick  and  dried.     The  cracks  are  filled  with  thin  clay 


FIG.  84. 

and   again  dried   to  ensure  a  solid  surface.      The  large 
ladles,  as  for  the  crane,  are  lined  with  fire-brick  laid 


FIG.  85, 

up  in  fire-clay,  as  in  the  case  of  the  cupola  lining.  A 
daubing  of  clay  is  placed  over  the  fire-brick  to  take 
the  cutting  and  wash  of  the  iron.  The  daubing  is  put 


CUPOLAS,  BLOWERS,  AND  MELTING  FURNACES    169 

on  the  same  as  the  lining  of  the  smaller  ladles.  In  re- 
ceiving ladles  for  the  cupola,  the  continual  fall  of  the 
iron  upon  one  point  as  it  comes  from  the  spout  cuts  away 
the  lining  very  rapidly.  Without  special  protection  the 
lining  will  be  cut  away  in  a  comparatively  short  time.  A 
good  method  of  daubing  this  ladle  is  to  have  the  place 
where  the  metal  strikes  built  up  with  small  pieces  of  fire- 


FIG.  86. 

brick  laid  into  the  clay  very  closely,  and  the  mass  well 
bound  together  with  the  clay  daubing  and  thoroughly 
dried  before  the  metal  strikes  it. 

The  blast  for  melting  the  iron  is  produced  by  blowers 
suitable  to  deliver  the  volume  of  air  desired  and  to  main- 
tain the  pressure  required  for  the  particular  furnace. 
There  are  two  types  of  blower  in  general  use:  first,  the 
positive  blast  or  root  blower,  and  second,  the  fan. 

Fig.  85  illustrates  one  style  of  a  root  blower  which  is 


FOUNDRY  PRACTICE 


driven  by  a  belt.  The  blast  is  produced  by  the  rotation 
of  the  vanes,  as  indicated  by  the  arrows  shown  in  the 
sectional  view  in  Fig.  86.  These  blowers  are  positive, 


FIG.  87. 

because  the  volume  of  air  delivered  at  the  discharge  side 
cannot  escape  back  between  the  vanes  to  the  admitting 
side,  even  if  the  pressure  is  increased  in  the  discharge 


CUPOLAS,  BLOWERS,  AND  MELTING  FURNACES    171 

pipe.  A  relief  valve  is  usually  placed  on  the  discharge 
pipe  which  relieves  excess  pressures. 

Fig.  87  shows  one  form  of  fan  blower  which  is  driven 
by  belt.  The  blast  is  produced  in  these  by  the  centrifugal 
force  given  the  air  at  the  end  of  the  vanes  and  acting 
tangentially  to  the  rotation  of  the  fan,  thus  discharging 
into  the  delivery  pipe.  The  air  supply  is  taken  in  at  the 
centre,  wrhich  is  left  open.  When  the  pressure  in  the  de- 
livery p'pe  becomes  equal  to  the  centrifugal  force  pro- 
duced by  the  fan,  the  air  will  not  be  delivered  into  the 
discharge  pipe,  hence  no  further  increase  of  pressure. 

Either  of  these  blowers  may  be  directly  connected  or 
may  be  driven  by  ropes  or  belts. 


CHAPTER  VI 

CHILLED  CASTINGS 

IN  many  castings  it  is  desirable  that  parts  of  the  sur- 
face shall  be  very  hard,  to  withstand  wear  and  tear, 
while  other  parts  shall  retain  its  general  toughness  or 
shall  be  of  soft  iron.  This  result  is  effected  by  chilling 
the  portion  of  casting  desired  to  be  hard.  The  chilling 
is  accomplished  by  placing  an  iron  chill  in  the  mold 
where  chilling  is  desired,  while  the  other  portions  of  the 
mold  are  formed  of  sand  as  usual.  The  metal  coming  in 
contact  with  the  iron  is  cooled  quickly  and  holds  the  car- 
bon in  the  combined  or  white  iron  form,  while  the  parts 
cooling  more  slowly  allow  the  carbon  to  change  back  to 
the  graphitic  or  gray  iron  form,  which  is  soft  and  tough. 

This  method  of  hardening  parts  of  castings  is  used  for 
many  forms  of  casting  and  under  various  conditions. 
The  most  extensive  use  is  that  of  chilling  the  rim  of  car 
wheels  and  the  face  of  rolls. 

The  sand  parts  of  the  mold  are  made  similar  to  other 
castings,  either  in  green  or  dry  sand,  as  the  case  may 
require.  The  chill  portions  are  placed  into  the  mold  as  a 
third  part  to  the  flask,  as  in  car  wheels  and  rolls,  or  are 
set  similarly  to  a  core  in  the  side  of  small  molds,  as 
machine  parts,  anvils,  etc.  The  chill  is  heated  in  an  oven 
to  a  temperature  of  about  200°  F.,  before  placing  in  the 

172 


CHILLED  CASTINGS  173 

mold.  The  moisture  from  the  mold  and  from  the  sand 
adjoining  the  chill  would  be  deposited  on  the  surface  if  it 
were  cold,  thus  causing  it  to  blow  and  to  force  the  molten 
iron  away  from  it  when  cast.  After  warming,  the  face  of 
the  chill  must  be  coated  in  order  to  prevent  the  iron  from 
sticking  to  the  surface  and  to  allow  the  chill  to  be  lifted 
from  the  surface.  A  coating  of  blacking  wet  with  mo- 
lasses water  gives  good  satisfaction.  Other  methods  of 
coating  that  work  better  in  particular  cases  are :  to  shell ac 
the  face  and  allow  to  harden  well  before  using;  to  varnish 
the  face  with  a  common  grade  and  when  nearly  dry 
sprinkle  with  plumbago;  or  to  use  a  thin  coating  of  a 
light  clean  oil,  as  a  heavy  oil  or  a  thick  coat  will  burn 
off,  thus  holding  the  iron  away  by  the  gases  formed. 

The  chill  should  be  so  placed  in  the  mold  that  the 
metal  shall  rise  on  the  chill  but  shall  not  lie  horizontally 
or  have  the  inflowing  metal  fall  upon  the  chill.  The 
gates  should  be  so  arranged  and  of  such  a  size  that  the 
chill  will  be  covered  quickly  to  prevent  the  metal  form- 
ing bubbles  on  the  surface  of  the  chill.  It  sjiould  be 
flushed  up  quickly,  or  the  chill  will  cause  cold-shots  and 
streaks  in  the  chill  surface. 

The  metal  in  contact  with  the  chill  forms  a  crust  or 
shell  quickly  and  contracts,  holding  the  remainder  of  the 
iron  while  still  in  the  molten  state.  If  there  is  any 
unevenness  in  the  pressure  on  this  shell,  it  may  cause 
cracking  or  bursting  of  the  surface,  as  is  sometimes 
noted  in  chilled  faces.  This  may  be  lessened  by  having 
the  flask  so  arranged  that  the  chill  is  level,  as  in  rolls  or 
car  wheels. 

The  chill  should  be  made  of  the  best  grade  of  iron 


174  FOUNDRY  PRACTICE 

having  little   contraction,   so   that   the   surface  will  not 
check  and  break  when  the  face  is  suddenly  heated  by  the 
molten  metal.     A  good  iron  for  making  chill  casting  will 
make  a  good  chill.     Wrought  iron  is  sometimes  used  for 
a  chill.     The  thickness  of  the  chill  is  much  dependent 
upon  the  depth  that  it  is  desired  to  chill  the  casting.     It 
must  be  of  such  a  size  that  it  may  conduct  away  the  heat 
necessary  to  cool  the  iron  from  the  molten  state,  about 
2500°  F.,  to  that  of  solidification,  about  1000°  F.,  and 
must  hold  it  at  that  temperature  so  that  the  iron  within 
will  not  remelt  the  chilled  skin.     Special  types  of  chill 
for  car  wheels  are  in  use  which  give  good  results.     They 
are  made  up  of  parts  instead  of  a  solid  ring,  and  some 
forms  are  so  arranged  that  the  chill  contracts  as  the  cast- 
ing contracts,  thus  following  the  surface  of  the  castings  as 
it   cools.     Another   form   has   open    chambers    through 
which  steam  is  circulated  to  warm  the  chill  before  cast- 
ing, then  cold  water  is  circulated  after  casting,  to  effect  a 
deeper  chill.     The  depth  of  chill  is  dependent  upon  the 
mixture  of  iron  used  and  the  rapidity  with  which  the  face 
of  the  casting  is  cooled.     The  depth  of  chill  on  rolls 
varies  from  one  half  inch  to  seven-eighths  inch  to  suit 
different  requirements.     Some    users   of    rolls   desire    a 
defined  chilled  skin  while  others  wish  the  chilled  portion 
to  shade  gradually  into  the  soft  interior  of  the  casting. 
Car  wheels  are  chilled  to  a  depth  of  about  three  fourths 
of  an  inch. 

The  mixtures  of  iron  for  chill  castings  can  be  success- 
fully made  only  by  use  of  chemical  analysis,  and  not  by 
judging  from  the  fracture.  Good  soft  iron  should  have 
1.8  per  cent  silicon;  while  this  will  not  chill  without 


CHILLED  CASTINGS  175 

excess  of  sulphur,  which  makes  a  very  poor  iron.  Chill 
iron  should  have  less  than  i  per  cent  silicon  and  not 
over  0.08  per  cent  sulphur.  The  total  carbon  should  be 
as  high  as  possible,  other  metalloids  being  constant. 
The  combined  carbon  should  rarely  exceed  0.6  per  cent, 
as  that  makes  the  iron  too  hard  and  too  brittle.  The 
mixtures  must  be  closely  watched  and  tested  every  day 
to  ensure  the  proper  proportion  of  impurities.  Iron 
melted  in  a  cupola  is  tested  before  pouring  into  the  chill 
molds.  The  test  is  for  depth  of  chill,  and  the  test  bar  is 
about  2  in.  square  and  6  in.  long,  having  one  side  against 
a  chill.  It  is  cooled  and  broken,  and  if  the  chill  is  insuf- 
ficient it  is  poured  into  other  molds  or  pig  beds  where  it 
may  be  remelted.  The  air  or  reverberatory  furnace  has 
many  advantages  for  this  class  of  work,  as  the  iron  may 
be  tested  and  varied  by  addition  of  special  irons  before 
tapping  for  the  purpose  of  pouring. 


CHAPTER  VII 

MALLEABLE  CASTINGS 

Malleable  cast  iron  is  a  form  that  becomes. tough  and 
partly  malleable  when  annealed  by  the  mallcablizing 
process.  The  iron  loses  its  brittleness  and  may  be  bent 
or  straightened  without  breaking.  Thus  it  may  better 
resist  shock  and  occupies  a  place  between  gray  iron  and 
wrought  iron,  having  a  higher  tensile  strength  than  the 
former  and  less  ductility  than  the  latter. 

The  effect  of  the  malleablizing  process  is  to  change  both 
the  chemical  composition  and  physical  properties  of  the 
iron.  The  most  important  of  these  changes  is  to  con- 
vert a  large  part  of  the  carbon,  which  originally  existed 
in  the  combined  form,  into  a  special  variety  of  the  gra- 
phitic form.  This  variety  does  not  occur,  as  ordinarily 
in  plates,  but  in  a  much  finer  state  of  division.  In  prac- 
tice, the  percentage  of  total  carbon  as  well  as  other  metal- 
loids is  somewhat  reduced.  The  results  of  these  changes 
are  to  make  some  of  the  physical  properties  of  the  cast- 
ing resemble  those  of  wrought  iron. 

The  iron  used  must  be  a  white  iron  whose  carbon  will 
be  in  the  combined  form.  The  per  centage  of  silicon  must 
be  low.  When  above  0.75  per  cent,  the  metal  will  have 
a  high  tensile  strength  but  small  elongation.  The  frac- 
ture has  a  steely  appearance  in  the  finished  casting  when 

176 


MALLEABLE  CASTINGS  177 

the  silicon  is  too  high.  Phosphorus  is  beneficial  up  to 
0.15  per  cent,  as  it  helps  maintain  fluidity  in  the  metal. 
Sulphur  is  very  detrimental  when  present  in  appreciable 
percentages.  An  iron  having  sulphur  or  phosphorus  too 
high  will  be  harder  and  have  cracks  at  the  surface  of  the 
casting.  The  presence  of  manganese  in  comparatively 
high  percentages  is  beneficial  to  the  resulting  casting. 
It  acts  as  a  neutralizer  on  the  silicon  to  prevent  its  effect 
upon  the  carbon.  Manganese  assists  the  carbon  change, 
and  shortens  the  time  necessary  for  its  completion. 
Scaly  castings,  when  properly  packed,  result  from  too 
low  a  percentage  of  manganese. 

The  process  of  annealing  is  effected  by  packing  the 
castings  with  oxidizing  reagents  into  covered  cast-iron 
boxes.  They  are  placed  in  ovens  which  are  sealed  and 
heated  by  some  form  of  direct-fired  furnace  which  holds 
the  temperature  uniformly  at  about  1850°  F.  for  a  period 
from  eight  hours  to  several  days,  dependent  upon  the 
size  and  character  of  the  castings.  The  ovens  are  so 
arranged  as  to  distribute  the  heat  evenly  and  not  to  be 
subjected  to  sudden  changes.  The  temperature  is  meas- 
ured by  a  pyrometer  which  will  indicate  the  high  tem- 
perature. Too  high  or  too  low  a  temperature  affects  the 
action  of  the  reagents  and  injures  the  resulting  castings. 
The  oven  is  heated  slowly  so  as  to  maintain  the  tempera- 
ture of  the  castings  at  nearly  that  of  the  oven  at  all  times, 
and  is  cooled  very  slowly  when  the  process  is  complete, 
to  avoid  a  chemical  change  due  to  the  sudden  change  of 
temperature.  These  ovens  may  be  fired  by  coke,  coal, 
oil,  or  gas. 

The  reagents  used  must  be  high  in  oxygen,  which  at 


178  FOUNDRY  PRACTICE 

the  temperature  of  the  annealing  will  combine  with  the 
carbon  of  the  iron  forming  CO  gas,  which  passes  off. 
Some  of  the  reagents  used  are  red  hematite  ore,  rolling 
mill  scale  well  oxidized  or  rusted,  and  steel  turnings 
heavily  rusted.  The  oxidizing  may  be  effected  by  a  weak 
solution  of  sal-ammoniac.  These  may  be  used  several 
times  by  the  addition  of  a  partly  fresh  unburnt  reagent. 
or  by  reoxidizing  with  sal-ammoniac  each  time.  The 
casting  must  be  completely  covered  with  the  reagent 
when  packed  in  the  boxes.  If  two  castings  touch,  those 
spots  will  not  be  properly  malleablized,  thus  making  an 
imperfect  casting. 

The  form  and  proportions  of  the  pattern  for  malleable 
work  require  special  attention.  Sharp  angles  must  be 
avoided  and  all  corners  filleted  with  adequate  radii.  The 
iron  always  shrinks  away  from  the  angle  in  both  direc- 
tions, thus  causing  a  crack  or  depression,  which  should 
be  avoided.  The  change  from  light  to  heavy  section 
should  be  gradual.  The  round  section  has  proved  to  be 
the  weakest  form,  hence  it  should  be  avoided.  As  the 
greatest  strength  of  malleable  castings  lies  in  the  skin, 
it  is  preferable  to  have  as  great  a  surface  as  possible  with 
no  great  thickness,  of  metal,  as  in  many  cases  it  is  prefer- 
able to  have  several  thin  ribs  rather  than  one  thick  one. 

The  gating  of  castings  to  be  malleablized  is  of  great 
importance  and  requires  the  most  skill  and  experience  of 
any  part  of  the  work.  For  this  reason  most  patterns  have 
gates  attached  which  are  put  on  by  experienced  men. 
The  cause  of  difficulty  in  gating  a  casting  or  running  in- 
tricate forms,  as  in  gray  iron,  is  the  hardness  of  the  iron, 
causing  it  to  shrink  more  and  set  more  quickly.  The 


MALLEABLE  CASTINGS  179 

branch  gate  should  not  extend  from  the  bottom  of  the 
feeder,  as  it  will  chill  from  the  sand,  thus  solidifying 
socner  than  the  metal  in  the  mold.  The  feeder  should 
extend  about  one-third  its  length  below  the  branch  gate 
and  should  be  as  close  as  possible  to  the  casting.  For 
light  patterns  the  branch  gate  should  not  exceed  half 
an  inch  in  length,  and  it  is  preferably  of  circular  section. 
When  it  is  difficult  to  feed  a  portion  of  a  mold  properly, 
a  chill  may  be  placed  at  that  point  to  solidify  it  more 
quickly  than  the  other  parts,  thus  preventing  fracture  or 
shrink-holes. 


CHAPTER  VIII 

CLEANING  CASTINGS 

WHEN  the  casting  comes  from  the  mold  it  has  more  or 
less  sand  adhering  to  its  surface,  or  the  cores  are  still  in 
the  casting.  It  must  be  cleaned  and  all  sand  removed 


FIG.  88. 

before  it  is  ready  for  the  machine  shop.  The  gates  and 
risers,  as  well  as  all  fins,  should  be  chipped  off.  This  is 
a  portion  of  the  cleaning  and  of  the  preparation  for  leav- 
ing the  foundry.  The  methods  of  cleaning  the  sand  from 

180 


CLEANING  CASTINGS 


181 


castings  may  be  classed  under  three  main  heads:  First, 
the  use  of  tumbling  barrels;  second,  hand  work;  third, 
the  use  of  pneumatic  appliances.  The  tumbling  barrel, 


or  rattler, 'is  driven  by  power  and  cleans  the  castings  by 
their  rolling  about  in  the  drum  as  it  turns  over.  Fig.  88 
represents  a  tumbling  barrel  driven  by  the  friction  wheels 
on  which  it  rests.  Fig.  89  shows  a  pair  of  tumbling 


182 


FOUNDRY  PRACTICE 


barrels  driven  by  gears  and  having  the  exhaust  connec- 
tion for  drawing  away  the  dust  as  it  is  freed  from  the 
castings. 


The  cleaning  by  hand  is  chiefly  done  by  use  of  wire 
brushes  and  emery  bricks,  or  rub-stones.  When  the  sand 
is  fused  hard  onto  the  casting,  it  may  require  chipping, 
filing,  or  scraping  with  iron  scrapers.  The  use  of  pneu- 
matic appliances  for  foundry  work  is  increasing  rapidly. 


CLEANING  CASTINGS  183 

The  greatest  convenience  for  cleaning  is  found  in  the 
sand-blast  appliances,  as  represented  in  Fig.  90;  also  as 
connected  to  a  tumbling  barrel  having  an  exhaust  con- 
nection. The  sand  blast  is  attached  to  the  tumbling  bar- 
rel at  the  centre  opposite  to  the  exhaust  pipe>  This 
gives  the  action  of  the  sand  blast  upon  the  castings  as 
they  move  about  in  the  tumbling  barrel. 

The  gates,  risers,  and  fins  on  castings  are  removed,  in 
general,  by  hand  chipping,  or  by  the  use  of  a  pneumatic 
hammer  shown  in  Fig.  95.  When  the  gates  on  castings 
cannot  be  broken  and  chipped  without  danger  of  break- 
ing into  the  casting,  it  is  sawed  off  or  ground  off  on  an 
emery  wheel.  Many  shops  are  equipped  with  cold  saws 
for  this  purpose.  All  shops  making  steel  castings  must 
be  provided  with  cold  saws  of  some  type,  because  the 
gates  and  risers  must  be  so  large  that  it  is  impossible  to 
chip  them  off  without  danger  of  spoiling  the  casting. 
The  emery  wheel  is  used  extensively  on  small  castings 
and  for  smoothing  over  the  chipping  on  other  castings. 
The  fixed  wheel  of  a  coarse  grade  is  generally  used.  The 
portable  emery  wheel,  or  grinder,  is  very  convenient  for 
large  castings. 


184 


FOUNDRY  PRACTICE 


CHAPTER  IX 

COMPRESSED  AIR  FOR  FOUNDRY  PURPOSES 

THE  use  of  compressed  air  in  a  modern  foundry  is 
considered  indispensable.  By  use  of  pneumatic  tools  and 
machinery  the  cost  of  foundry  products  is  greatly  reduced. 
The  appliances  operated  by  compressed  air  are  the  pneu- 
matic crane,  hoist,  molding  machine,  sand  sifter,  chipping 
hammer,  screen  shaker,  sand  rammer,  and  sand-blast 
machine. 

The  pneumatic  crane  is  shown  in  Fig.  91.  All  move- 
ments of  the  crane  are  controlled  by  the  operator  in  the 
carriage. 

The  pneumatic  hoist  is  shown  in  Fig.  92.  In  lifting 
copes  and  drawing  patterns,  the  most  perfect  and  regular 
motion  is  required  to  prevent  "sticks,"  "tears,"  and 
"drop-outs."  A  jerk  is  fatal  to  the  mold.  This  hoist 
may  be  moved  with  a  speed  as  slow  and  as  regular  as  the 
hour  hand  of  a  clock,  and  a  change  of  speed  may  be 
made  without  a  sudden  jerk  or  jar.  It  may  be  operated 
rapidly  as  well. 

A  pneumatic  molding  machine  is  shown  in  Fig.  93. 

The  pneumatic  sand  sifter  is  shown  in  Fig.  94.  This 
machine  is  operated  by  an  air  cylinder  directly  con- 
nected to  the  sifter.  The  air  is  supplied  to  the  cylinder 

185 


i86 


FOUNDRY  PRACTICE 


FIG.  92. 


COMPRESSED  AIR  FOR  FOUNDRY  PURPOSES       187 


FIG.  93. 


i88 


FOUNDRY  PRACTICE 


by  a  rubber  hose,  making  the  machine  portable  so  that  it 
may  be  used  in  any  location  in  the  foundry. 


FIG.  9-1. 


FIG.  95. 

The  pneumatic  chipping  hammer  is  shown  in  Fig.  95. 
The  pneumatic  sand  rammer  in  Fig.  96  is  fitted  to 


COMPRESSED  AIR  FOR  FOUNDRY  PURPOSES       189 

hang  from  a  support,  and  has  both  pein  and  butt  as  the 
operator  may  desire. 


FIG.  96. 

The  sand  blast  machine  is  shown  in  Fig.  90. 
Fig.   97   shows   a  pneumatic    shaker    mounted   on   a 
tripod  so  that  it  may  be  placed  wherever  desired  and  may 


FIG.  97. 

be  fitted  to  hold  a  riddle,  so  that  a  riddle  of  any  desired 
number  may  be  placed  in  it. 

Fig.  98  represents  a  pneumatic  hoist  having  a  wind- 
ing drum  driven  by  cylinders. 


FOUNDRY  PRACTICE 


FIG.  98. 


COMPRESSED  AIR  FOR  FOUNDRY  PURPOSES 


FIG.  99. 


FIG.  100. 


192 


FOUNDRY  PRACTICE 


The   machines  shown  in  figures  99  to  104   represent 
a  few  of  the  special  foundry  machines.     The  sand  sifter 


FIG.  101. 


FIG.  102. 

shown  in  Fig.  99  is  driven  by  belt  but  may  be  fitted 
with  a  hand  wheel  for  hand  power. 


COMPRESSED  AIR  FOR  FOUNDRY  PURPOSES       193 


FIG.  103. 


IQ4  FOUNDRY  PRACTICE 

Fig.  ioo  represents  a  rotary  sand  sifter  which  is  belt- 
driven. 

Figs.  101  and  102  are  sand  mixers  having  paddles 
which  rotate  to  mix  the  sand  thoroughly. 

Fig.  103  is  a  centrifugal  mixer.  The  sand  entering 
from  the  hopper  falls  upon  a  rotating  disk  which  throws 
the  sand  by  centrifugal  force,  thus  mixing  it. 

These  mixers  are  of  especial  advantage  in  mixing 
facings  or  sands  of  different  kinds  where  a  thorough 
mixing  is  necessary. 

Fig.  104  represents  a  sand  crusher.  The  pan  holding 
the  sand  rotates  under  the  rolls  and  the  sand  is  loosened 
by  fixed  paddles  between  the  rolls.  These  paddles  may 
serve  as  a  mixer  also  and  are  used  in  mixing  the  sand 
and  clay  for  the  facing  of  molds  for  steel  castings. 


CHAPTER  X 

STEEL  CASTINGS 

THE  manufacture  of  steel  castings  is  greatly  increas- 
ing in  extent  and  variety.  The  industry  is  young,  so 
that  it  has  not  been  developed  to  its  fullest  extent.  A 
few  brief  points  will  here  be  given  which  may  give 
the  iron  worker  an  idea  of  methods  necessary  in  making 
steel  castings. 

The  mold  is  formed  in  sand,  which  may  be  green  or 
dried  to  suit  the  type  of  work.  The  same  mixtures  are 
used  in  both  cases.  The  sand  is  a  very  open  mixture 
with  sufficient  clay  to  form  a  binder.  The  following 
mixture  may  be  taken  as  a  guide:  Mix  3  parts  coarse 
sharp  sand  98  per  cent  SiO2,  2  parts  fine  sharp  sand  95 
per  cent  SiC>2,  i  part  red  clay. 

This  mixture  should  be  thoroughly  blended  and 
crushed  in  a  sand  crusher.  This  is  used  as  a  facing 
while  the  heap  sand  from  former  molds  is  used  as  a 
backing  sand. 

The  mold  is  rammed  very  hard,  so  that  in  the  green 
form  it  is  nearly  as  hard  as  a  dry  sand  mold  for  iron. 
The  sand  is  tempered  to  hold  together  but  is  kept  as  dry 
as  possible.  When  the  mold  is  dried  it  becomes  very 
hard  and  has  great  strength  to  resist  pressure. 

Steel  will  cut  the  and  much  more  readily  than  iron. 

195 


196  FOUNDRY  PRACTICE 

All  edges  and  projections  must  be  well  nailed  so  that 
the  heads  hold  the  surface  of  the  sand.  All  large  plane 
surfaces  must  be  nailed  quite  closely  to  prevent  cutting 
in  the  drag  and  drawing  down  the  cope. 

Owing  to  the  hard  ramming,  the  pattern  is  hard  to 
remove,  hence  the  exact  form  of  casting  is  not  obtained 
so  easily  as  in  iron.  Particular  forms,  as  gear  teeth,  are 
more  difficult  to  obtain  in  steel  than  in  iron. 

The  metal  must  be  of  a  higher  temperature  than  iron 
in  order  to  maintain  fluidity.  Hence  it  sets  more  quickly 
and  usually  is  duller  when  poured  than  iron.  The  gates 
must  be  made  correspondingly  large  to  allow  the  mold  to 
fill  quickly,  or  the  light  or  sharp  parts  will  not  run.  The 
shrinkage  is  about  double  that  of  iron,  and  takes  place 
very  soon  after  pouring.  A  riser  must  be  provided  of 
adequate  size  to  feed  the  shrinkage.  The  feeding  rod 
cannot  be  used  as  effectively  as  in  iron,  hence  the  riser 
must  act  more  as  a  sinking  head. 

Castings  of  such  form  that  they  crush  the  sand  of  the 
mold  when  shrinkage  takes  place  are  sometimes  found 
to  be  broken  or  drawn  weak  in  places  when  they  come 
from  the  mold.  This  is  due  to  the  casting  being  unable 
to  crush  the  sand  to  permit  the  shrinkage.  This  may  be 
prevented  by  cutting  a  gutter  on  the  parting  of  the  flask 
about  two  inches  from  the  casting  and  connecting  this 
gutter  by  an  opening  through  the  cope.  As  soon  as  the 
casting  has  set  the  gutter  is  filled  with  water,  which 
softens  the  sand,  making  it  easier  to  crush.  In  some 
cases,  castings  of  quite  intricate  and  large  size  have  been 
made  more  successfully  in  green  sand  than  in  dry  owing 
to  the  mold's  resistance  to  crushing. 


STEEL  CASTINGS  197 

The  chief  methods  of  melting  steel  for  steel  casting  are 
by  the  cupola  or  by  a  converter.  Steel  is  successfully 
incited  in  the  cupola  the  same  as  iron.  The  higher  tem- 
perature required  offers  many  difficulties  which  are  a 
drawback  to  the  process.  It  is  hard  to  obtain  good 
fluidity  in  the  cupola.  The  converter  gives  steel  of  the 
composition  desired,  and  the  fluidity  is  much  more  per- 
fect. 

Formerly  steel  was  melted  in  a  crucible,  similarly  to 
brass,  but  this  is  an  expensive  method  which  is  not  used 
except  in  isolated  cases.  The  bottom  blow,  side  blow, 
and  open-hearth  converter  are  the  most  economical 
producers  of  steel  for  castings.  Where  the  furnace  can 
be  kept  in  operation  continuously,  the  open-hearth  fur- 
nace presents  many  advantages.  For  intermittent  heats, 
the  bottom  or  side  blow  converter  gives  the  best  results. 
The  side-blow  converter  proves  preferable,  as  the  iron 
used  may  be  lower  in  silicon  and  yet  obtain  a  good  steel; 
and  besides  the  steel  becomes  superheated,  which  better 
permits  handling  and  pouring. 

In  the  open-hearth  furnace,  the  metal  is  melted  and 
reduced  in  its  bath.  Any  kind  of  iron  or  steel  scrap  may 
be  charged.  The  product  is  tested  by  a  sample  and  is 
poured  when  the  steel  is  of  the  nature  desired.  The 
process  is  slow,  taking  from  eight  to  twelve  hours  to 
reduce  a  charge. 

In  the  blow  converter,  the  reduction  takes  place  in  a 
very  few  minutes.  The  iron  for  the  charge  is  melted  in 
a  cupola  and  put  into  the  converter  in  the  molten  state. 
The  progress  of  the  conversion  is  told  by  the  gases  which 
pass  off  at  the  top.  When  the  desired  amount  of  impur- 


198  FOUNDRY  PRACTICE 

ities  have  been  removed,  a  charge  of  spiegeleisen  is  mixed 
with  that  in  the  converter,  giving  a  product  of  the  de- 
sired percentage  of  carbon.  The  steel  may  be  varied  by 
changing  the  percentage  of  spiegeleisen  charged.  The 
blast  is  turned  off  before  charging  the  spiegeleisen.  The 
two  charges  in  the  converter  are  allowed  to  mix,  then  it 
is  poured  out  ready  for  the  molds. 

The  iron  used  for  the  converter  should  have  about 
2  per  cent  of  silicon,  phosphorus  below  0.06  per  cent, 
manganese  as  low  as  possible,  and  sulphur  very  low. 

The  following  mixture  may  be  substituted  for  the  ore 
spiegeleisen:  95  Ibs.  of  ferrous  silicate,  45  Ibs.  of  man- 
ganese, 65  Ibs.  of  pig  iron  which  is  low  in  phosphorus 
and  high  in  silicon. 


CHAPTER  XI 

BRASS  FOUNDING 

Brass  molding  is  so  similar  to  iron  molding  that  a 
description  is  unnecessary.  One  is  different  from  the 
other  only  in  the  particular  that  gating  and  venting  must 
be  given  more  consideration.  The  sand  used  for  brass 
molding  is  much  finer,  and  when  rammed  in  the  flask 
it  must  be  well  vented,  or  unsound  castings  will  result. 
The  metal  used  in  brass  casting  is  of  a  nature  that  will 
not  permit  an  unnecessarily  high  temperature,  as  the 
castings  will  not  then  be  sound.  Long  runners  cool  the 
metal  so  as  to  prevent  its  filling  the  mold  properly.  Short 
runners  and  a  liberal  amount  of  gating  are  desirable. 
The  sand  most  used  for  brass  molding  is  the  Albany. 
This  sand  is  fine  and  gives  entire  satisfaction  for  ordi- 
nary brass  work;  but  for  heavy  work  in  brass,  and  when 
the  casting  is  to  be  finished,  the  mold  is  made  in  a  coarse 
and  more  open  sand.  Sometimes  it  is  advisable  to  make 
the  mold  in  dry  sand  for  heavy  work.  In  pouring  the 
metal  into  the  mold,  it  should  be  run  as  rapidly  as  possible 
until  the  mold  is  filled.  On  heavy  castings  it  is  very 
necessary  to  provide  the  mold  with  a  riser  or  shrinking 
head,  as  the  shrinkage  in  brass  or  bronze  is  greater  than 
in  cast  iron.  After  the  metal  has  been  cast  it  may  be 
cooled  in  water  as  soon  as  it  has  solidified. 

199 


2OO 


FOUNDRY  PRACTICE 


By  slowly  cooling  the  brass  becomes  hard,  and  by 
sudden  cooling  the  brass  may  be  softened.  The  immers- 
ing in  water  gives  the  sudden  cooling,  and  besides  re- 
moves the  sand  from  the  casting. 

In  preparing  the  mold  for  brass  the  ordinary  facings 
used  in  iron  molds  are  unnecessary.  Plumbago  is  sel- 
dom used  except  in  heavy  castings;  for  light  and  medium 


FIG.  105. 

work,  flour,  pulverized  soapstone,  charcoal,  and  some- 
times plaster  of  Paris  or  bone  dust  are  used.  In  very 
light  castings  nothing  is  necessary  except  very  fine  mold- 
ing sand. 

Very  good  results  are  obtained  in  small  work  by  using 
a  very  fine  sand  and  spraying  the  mold  with  gasoline, 
lighting  it,  and  allowing  it  to  burn  off.  This  skin-dries 
the  mold  and  prevents  the  metal  from  washing  or  cutting 
the  mold  in  pouring. 


BRASS  FOUNDING 


2OI 


The  snap-flask  is  sometimes  used  in  brass  molding, 
but  for  small  and  for  light,  thin  castings  the  flask  shown 
in  Fig.  105  is  more  convenient.  This  flask  is  provided 
with  openings  at  one  end  which  are  used  for  pouring- 


i"v.-v/vj   B;I  yi  n  tJtl   :|    i-lJJ 


FIG.  106. 


holes.  When  the  mold  is  ready  to  cast  it  is  set  on  end 
with  the  openings  up.  This  gives  more  force  to  the  metal 
and  greater  pressure  in  the  mold.  This  also  avoids  the 
chilling  of  the  metal  before  it  reaches  the  mold. 


202 


FOUNDRY  PRACTICE 


Brass  founding  differs  somewhat  from  iron  founding, 
for  the  reason  that  the  metal  is  of  a  different  character 
and  must  be  treated  differently.  Brass,  or  copper  alloys, 
cannot  be  melted  in  a  cupola  furnace  and  sound  castings 


FIG.  107. 

be  obtained,  except  in  the  case  of  heavy  castings  with 
thick  metal.  The  metal  coming  in  contact  with  the  fuel 
is  impregnated  with  impurities,  which  causes  unsound 
castings.  A  simple  form  of  furnace  for  melting  brass  is 
shown  in  Fig.  106.  The  more  improved  furnace  is 


BRASS  FOUNDING  203 

shown  in  Fig.  107.  To  prevent  the  metal  from  coming 
in  contact  with  the  fuel,  a  crucible  is  used.  The  crucible 
containing  the  metal  is  placed  in  the  furnace,  as  shown  in 
Fig.  106.  The  crucible  is  handled  by  means  of  tongs,  as 
shown  in  Fig.  108.  The  furnace  is  connected  with  a 
chimney  or  smoke  stack  of  sufficient  height  to  furnish 
draft.  Mechanical  draft  is,  however,  applied  in  some 
cases.  The  furnace  shown  in  Fig.  107  is  supplied  with 
both  natural  and  mechanical  draft.  This  arrangement 
is  best.  While  the  natural  draft  is  cheaper,  there  are 
days  when  the  draft  is  inadequate  and  the  melting  slow. 


FIG.  1 08. 

At  such  times,  it  is  desirable  to  use  mechanical  draft  for 
faster  melting.  Foundry  coke  or  anthracite  coal  is  used 
in  this  type  of  furnace. 

In  Fig.  106  the  portion  marked  A  is  the  fire  chamber, 
B  the  ash  pit  through  which  the  air  is  admitted  to  the 
grate  C,  and  D  the  flue  connecting  with  the  chimney  or 
stack.  The  ash  pit  in  front  and  underneath  the  fire 
chamber  is  covered  by  a  grating  which  may  be  lifted  off 
when  it  is  necessary  to  remove  the  ashes  from  the  pit. 
The  fire  chamber  cover  E  is  provided  with  an  upright 
handle  to  enable  the  operator  to  remove  the  cover  when 
the  furnace  is  hot.  The  fire  chamber  is  constructed  of 
fire-brick  and  is  cylindrical  in  form.  The  bottom  plate 
F,  which  supports  the  fire  chamber,  is  square,  having  a 


204 


FOUNDRY  PRACTICE 


round  opening  at  its  centre  the  same  diameter  as  the 
chamber.  This  plate  is  made  of  cast  iron  and  is  sup- 
ported in  the  brick  wall  at  the  back  and  sides  of  the  ash 
pit.  The  grate  underneath  the  plate  is  composed  of 


FIG.  109. 

single  iron  bars  placed  the  proper  distance  apart  and 
supported  by  cross  bars  at  front  and  back  extending  into 
the  sidewalls  of  the  pit.  The  single  bar  grate  is  pre- 
ferred by  many,  on  account  of  the  convenience  in  clean- 
ing the  fire  without  rebuilding.  After  one  heat  has  been 


BRASS  FOUNDING 


205 


taken,  it  is  desirable  to  clear  the  furnace  of  cinders  and 
ashes  which  form  on  the  grate.  This  is  difficult  to  do 
with  the  drop  gate,  as  shown  in  Fig.  107.  The  single 
bars  may  be  jarred  sidewise  with  a  long  bar  reaching 


FIG.  no. 

through  the  grating  on  the  ash  pit,  thus  saving  much 
time. 

To  prepare  for  melting  in  this  type  of  furnace,  remove 
the  grate  bars,  clear  the  furnace  of  ashes  and  clinkers, 


2O6 


FOUNDRY  PRACTICE 


adjust  the  bars  in  their  place,  put  in  a  sufficient  amount 
of  wood  to  start  the  coal  or  coke  to  burning,  and  add 
enough  fuel  to  form  a  bed  10  or  12  inches  in  depth. 
After  the  fuel  is  well  ignited,  place  the  crucible  with 
metal  on  the  bed  of  coals  and  add  fuel  around  the  cru- 
cible to  near  its  top.  As  the  fuel  burns  away  at  the 
bottom  of  the  furnace,  the  crucible  must  be  raised  slightly 
and  more  fuel  added  around  its  outside.  While  this  is 
being  done,  care  must  be  taken  to  prevent  fuel  falling 


FIG.  in. 

inside  the  crucible,  as  this  is  a  source  of  damage  to  the 
metal.  More  metal  may  be  added  when  that  in  the 
crucible  melts  and  settles.  When  the  metal  has  become 
fluid  enough  to  run  well,  it  should  not  be  allowed  to 
remain  in  the  furnace,  but  should  be  removed  with  the 
crucible  tongs  and  poured.  If  allowed  to  stand,  or  if 
overheated,  the  metal  will  be  damaged. 

There  are  still  more  modern  and  improved  brass  melt- 
ing furnaces  than  those  mentioned.     Among  others  are 


BRASS  FOUNDING  207 

the  Schwartz  metal  melting  and  refining  furnace  and  the 
Charlier  rolling  furnace.  These  furnaces  are  heated  by 
fuel  oil  or  gas.  They  are  very  efficient  and  economical 
on  account  of  rapid  melting.  The  Schwartz  furnace  is 
shown  in  Fig.  109.  This  furnace  is  lined  with  fire-brick 
and  is  supported  by  trunnions  having  a  bearing  on  pedes- 
tals. Air  and  oil  are  supplied  at  an  opening  through  the 
trunnion  at  one  end.  The  flow  of  oil  is  obtained  from  a 
standpipe,  by  pumping,  or  by  air  pressure  in  the  tank. 


FIG.  112. 

The  air  is  supplied  from  a  blower  or  from  a  storage  tank 
of  compressed  air,  and  is  regulated  by  a  valve.  Fig.  no 
is  a  general  view  of  the  furnace  and  its  arrangement. 

The  Charlier  rolling  furnace  is  shown  in  Fig.  in. 
This  furnace  consists  of  a  metallic  casing  lined  with  fire- 
brick and  having  an  opening  in  the  centre  of  rotation  at 
one  end,  through  which  the  fuel  and  air  are  admitted  to 
the  melting  chamber.  The  arrangement  of  this  furnace 
is  similar  to  the  one  previously  shown.  Fig.  112  shows 
a  general  plan  of  a  plant  equipped  with  a  Charlier  fur- 
nace. 


CHAPTER  XII 
CAST-IRON  ALLOYS 

To  toughen  cast  iron:  10  to  15  per  cent  of  wrought  iron 
scrap  (stirred  in) ;  J  to  i  per  cent  of  copper  (stirred  in)  • 

To  toughen  cast  iron  or  to  form  semi-steel:  Add  from 
5  to  30  per  cent  of  steel  scrap  to  the  charge  of  iron  in 
the  cupola. 

To  harden  cast  iron:  Mix  \  pint  vitriol,  i  peck  common 
salt,  J  Ib.  saltpetre,  2  Ibs.  alum,  J  Ib.  prussic  potash, 
\  Ib.  cyanide  potash.  Dissolve  the  mixture  in  10  gallons 
of  soft  water.  Heat  the  iron  to  a  cherry-red  and  dip 
into  the  solution.  For  a  harder  and  deeper  skin  on 
the  iron,  repeat  the  heating  and  dipping  two  or  more 
times. 

To  soften  or  to  anneal  cast  iron:  Heat  to  a  cherry-red, 
then  pack  in  a  coating  of  bone-black  and  cover  with 
ashes  to  allow  cooling  very  slowly. 


208 


TABLES 

MELTING-POINTS  OF  DIFFERENT  BRANDS  OF  IRON 


Combined 
Carbon. 
Percentage. 

Graphite. 
Percentage. 

Character 
of  Fracture. 

Melting- 
point. 
Deg.  F. 

Remarks. 

1.  60 
4-67 

3.16             Gray 
.03             White 

22IO 
2000 

Samples  cast  from  same 
ladle 

i-57 
4.20 

2.90 

.20 

Gray 
White 

2250 
1990 

Samples  cast  from  same 
ladle 

1.20 

3-9° 

2.90 
.16 

Gray 
White 

2250 
2000 

Samples  cast  from  same 
ladle 

MELTING-POINTS  OF  SOLIDS 


Cast  iron 2250  deg. 

Wrought  iron 39&1  deg. 

Gold 2587  deg. 

Silver 1250  deg. 

Steel 2501  deg. 

Brass 1897  deg. 

Copper 2550  deg. 

Glass 2377  deg. 

Platinum 3°77  deg. 


Lead 600  deg. 

Zinc 741  deg. 

Cadmium 602  deg. 

Saltpetre 600  deg. 

Tin 420  deg. 

Sulphur 225  deg. 

Potassium 135  deg. 

Antimony 951  deg. 

Bismuth 476  deg. 


METAL  ALLOYS  (VALUES  REPRESENT  PROPORTIONAL  PARTS) 


Copper. 

Tin. 

Zinc. 

Lead. 

Anti- 
mony. 

Bis- 
muth. 

Brass  valves  

o 

i 

.  ^O 

Brass  bearings  

IO 

I.  ^O 

•  ^o 

Bell  metal 

1C 

Yellow  brass 

16 

2     "CO 

17 

2    <?O 

Gun  metal  . 

Q 

I 

Fine  solder  .  .  . 

I 

I 

Plumber's  solder  ... 

I 

2 

Cast-iron  solder 

2 

I 

Babbitt  metal                          .    .  . 

I 

IO 

I 

2 

I 

Type  metal                 

9 

I 

Hard  bronze  for  lathe  bearings  . 

80 

20 

209 


2IO 


FOUNDRY  PRACTICE 


CHILLED-ROLL  IRON 


No. 
of 
Test. 

Approx. 
Diameter 
of  Bar. 
Inches. 

Exact 
Diameter 
of  Bar. 
Inches. 

Breaking 
Load. 
Pounds. 

Area 
of  Bar. 
Sq.  Inches. 

Strength 
per  Square 
Inch. 
Pounds. 

Deflection. 
Inches. 

I 

2 

3 

if 

if 
ifl 

1.140 

i-655 
1.968 

3-25° 
9.500 
I5-250 

I.  021 

2.151 
3.042 

3-183 
4-417 
5-013 

,105 
.090 
.085 

GUN-CARRIAGE  IRON 


4 

it 

I.  122 

2.780 

.988 

2.812 

.100 

5 

if 

1.664 

9.250 

2.174 

4.264 

.no 

6 

ill 

1.859 

11.820 

2.714 

4-355 

.100 

CAR-  WHEEL  IRON 

7 

il 

I-I74 

2.200 

1.082 

2-033 

•053 

8 

if 

1.690 

8.100 

2.244 

3.610 

.070 

9 

ilt 

2.008 

13-500 

3-I67 

4.263 

.072 

HEAVY  MACHINERY  IRON 


10 

II 

I.I87 

2.800 

1.106 

2.530 

.092 

II 

I-7°5 

7.IOO 

2.282 

3.111 

.072 

12 

iff 

2.001 

I  I  .  90O 

3-143 

3-786 

.079 

STOVE-PLATE  IRON 


I3 

I* 

1.182 

2.500 

1.097 

2.288 

.117 

14 

if 

1-745 

6.050 

2.391 

2-53° 

.078 

i5 

iff 

2.047 

9.900 

3-288 

3.011 

.081 

BESSEMER  IRON 


16 

it 

i-i75 

2.150 

1.084 

1.983 

.100 

17 

if 

1.698 

5-5oo 

2.263 

2.430 

.100 

18 

lit 

1.991 

8.900 

3.112 

2.860 

-085 

19 

i  m.square 

-994 

i-757 

.988 

1.778 

.150 

CHEMICAL  ANALYSIS  OF  IRONS  DESCRIBED  ABOVE 


Class  of  Iron. 

Silicon. 

Sul- 
phur. 

Man- 
ganese. 

Phos- 
phorus. 

Com 
bined 
Carbon 

Graph- 
itic 
Carbon 

Total 
Carbon 

Chill  iron  

.84 

O7l 

281; 

^4.7 

61 

2.45 

3.06 

Gun-metal 

77 

OCQ 

408 

AC? 

76 

2  47 

3-  23 

Car-wheel 

78 

I  -7  2 

306 

364 

I   O7 

2    36 

3-43 

General  machinery. 
Stove-plate 

1.30 

2    47 

-053 

004 

.224 
265 

-433 
so8 

-58 
IQ 

3-3T 

4.  CO 

3-89 
4.19 

Bessemer  iron  .... 

1-52 

.059 

.326 

-083 

-49 

3-73 

4.22 

CAST-IRON  ALLOYS 


211 


SIZE  AND  CAPACITY  OF  FOUNDRY  LADLES 


Capacity 
in 
Pounds. 

Inside  Dimensions. 

Allows  for  Daub- 
ing. 

Allows 
at  Top 
over 
Capacity. 
Inches. 

Diameter. 

Depth. 
Inches. 

At  Bot- 
tom. 
Inches. 

At  Sides. 
Inches. 

Top.       j  Bottom. 
Inches.        Inches. 

_ 

5° 

8.25 

6.25 

6 

-50 

-375 

-50 

3 

j3 

TOO 

IO 

9 

9-5° 

-So 

1.50 

t*  S 

IS0 

II 

IO 

10.50 

-50 

-50 

S3 

200 

12 

ii 

11.50 

-5° 

-5° 

•«3 

250 

13 

12 

12.50 

-5° 

-5o 

c 

— 

300 

14 

12.50 

*3 

-50 

-So 

a 

35° 

14-5° 

13 

i3-5o 

-50 

-So 

400 

15-5° 

M 

14-50 

-25 

-75 

-75 

500 

16.50 

15 

15-5° 

-25 

-75 

-75 

600 

-7-5° 

16 

i7 

-25 

-75 

-75 

8 

700 

18 

16.50 

17-5° 

-25 

-75 

-75 

i 

800 

18.50 

n 

18 

-25 

-75 

1-75 

p3 

1,000 

20.50        18.50 

19-5° 

-50 

2 

C 

1,200 

21.50 

19-5° 

21 

-50 

2 

8 

1,500 

23 

21 

22 

-50 

2 

^ 

2,OOO 

25-5° 

23-50 

24-5° 

-50 

2.50 

2,500 

27 

25 

26 

-50 

2.50 

3,000 

28.50 

26 

27-50 

-50 

2.50 

3>5°° 

3° 

27-50 

29 

-50 

2-50 

3 

4,000 

31-5° 

28.50 

30 

-50 

3 

c 

3 

4,5°° 

33-50 

30-50 

32 

2 

-5° 

3 

I 

5,000 

34-50 

31 

33 

2 

-5° 

3 

M< 

^fj 

6,000 

36-5o 

33 

35 

2 

-5° 

3 

8,000 

40.50 

36.50 

38-50 

2.50 

-75 

3 

IS 

10,000 

43-50 

39 

41 

2.50 

-75 

3-50 

«    §0 

12,000 

45-5° 

4i 

43-50 

2.50 

-75 

3-50 

1 

14,000 

48          j    43 

45-50 

2.50 

-75 

3-50 

^-i 

1 

l6,000 
18,000 

5° 
52 

45 
46.50 

47-50 
49 

2.50 
2-50 

-75 
-75 

3-50 
3-50 

u 

20,000 

53-50 

48 

50-50 

2.50 

-75 

3-5° 

24,000       57 

5' 

54 

2.50 

2 

3-5° 

SHRINKAGE  OF  CASTINGS  (APPROXIMATE  VALUES  ONLY) 


Metal. 

Inches  per  Lineal  Foot. 

Cast  iron  

I2C 

Brass 

i8?< 

Tin 

IO 

Zinc  

.xy 

•JT  oC 

Steel  

•ox^o 

9< 

•  m3 

212 


FOUNDRY  PRACTICE 


WEIGHTS  OF  CASTINGS  FROM  PATTERNS  WHERE  NO 
CORES  ARE  USED 


A  Pattern  Weighing 
1  Pound  made  of 

Will  Weigh  when  Cast  in 

Cast  Iron, 
Pounds. 

Zinc, 
Pounds. 

Copper, 
Pounds. 

Yellow 
Brass, 
Pounds. 

Gun 
Metal, 
Pounds. 

12-5 
15.0 

9.9 
14.0 

'9-5 
16.5 

10.9 

Mahogany,  Nassau  .  .. 
Honduras  . 
Spanish  .  . 
Pine,  red  

10.7 
12.9 
8-5 
12.5 
16.7 
14.1 
9.0 

10.4 
I2.7 

8.2 
12.  I 

16.1 
13-6 
8.6 

12.8 

15-3 
IO.I 

14.9 
19.8 

16.7 

10.4 

12.2 
I4.6 

9-7 
14.2 
19.0 
16.0 

IO.I 

'  '      white  

'  '      yellow 

Oak.. 

WEIGHTS  OF  ONE  CUBIC  FOOT  OF  METALS  WITH 
THEIR  TENSILE  STRENGTH 


Metal. 

Weight  of  1  Cubic 
Foot  in  Pounds. 

Tensile  Strength 
per  Square  Inch 
in  Pounds. 

Cast  iron 

4<\O 

16,500 

Ordinary  brass  ...                  .... 

C2< 

36,000 

Wrought  iron  

480 

50,000 

Hard  structural  steel  

4QO 

78,000 

Aluminum 

166  t 

26  800 

WEIGHT  IN  POUNDS  OF  ONE  CUBIC  INCH  OF  DIFFERENT 

METALS 


Brass  (average) 3°23 

Bronze 306 

Copper,  cast 3135 

Gold,  pure 6965 

Iron,  cast 2622 

Iron,  wrought 282 

Lead,  cast 415 

Steel 281 

Tin,  cast 263 


Zinc,  cast 26 

Antimony 242 

Bismuth 355 

Manganese 289 

Silver 378 

Platinum 735 

Cadmium 312 

Potassium 031 


CAST-IRON  ALLOYS 


2I3 


MIXTURES  FOR  PHOSPHOR-BRONZE  BEARING  METAL 


Number  of 
Mixture. 

Copper. 
Per  Cent. 

Lead. 
Per  Cent. 

Tin. 
Per  Cent. 

Phosphorus. 
Per  Cent. 

I 

79.0 

10.  O 

10 

I.O 

2 

79-7 

9-5 

IO 

.8 

3 

79-7 

IO.O 

10 

•3 

SIZE  AND  CAPACITY  OF  CRUCIBLES 


Number  of  Crucible. 

Outside  Height. 
Inches. 

Greatest  Outside 
Diameter. 
Inches. 

Capacity  in 
Molten  Metal. 
Pounds. 

x          .    

3-  ">o 

•7 

2 

•3      2< 

4   62^ 

•7      7C 

C.I2S 

4   2C, 

12 

c 

6       5 

^"'J 
4  62^ 

I  c 

6             

6.  so 

e.  I2C 

18 

8     

7.25 

c.87i; 

24, 

IO 

8    2C. 

6    2? 

•7Q 

I  2 

8  621; 

6  c,o 

3* 

16 

14 

o  i2c, 

7  2<; 

jr* 

42 

16                         .    . 

0.625; 

7   7^ 

48 

18             

'IO 

8.I2C, 

tA 

20  

10.625 

8.625 

fc 

2C. 

ii  1  25 

7? 

•?O 

II    75 

O    ^7"? 

/O 

oo 

7C 

12    2$ 

O   7c 

IO? 

4O 

12.625 

V-  /O 

0.871? 

1  20 

4<;  .  . 

I* 

10.  50 

I?c 

C.Q 

13    75 

IO   7^ 

I  CO 

60 

14    I  25 

II    2i? 

i^0 
1  80 

70 

14   75 

II    75 

2IO 

80  

1C.  CQ 

12    ?O 

24O 

100  

16.125 

12 

•5QO 

GLOSSARY 

Air-dried. — The  surface  drying  of  cores  left  in  open  air 
too  long  before  placing  in  oven.  Molds  left  open  also  dry 
out  on  surface,  causing  crumbling  or  washing  when  metal  is 
poured. 

Air  hoist. — A  piston  and  cylinder  suspended  from  an 
overhead  track  or  traveling  crane  and  operated  by  compressed 
air.  For  hoisting  ladles,  flasks,  or  weights  in  the  foundry. 

Alloy. — Any  compound  of  two  or  more  metals,  as  copper 
and  zinc  to  form  brass. 

Anchor. — A  contrivance  used  to  hold  parts  of  the  mold 
down  or  together.  See  PULLEY  ANCHOR. 

Arm. — The  portion  of  a  pulley  which  connects  the  hub  and 
the  rim. 

Ash  pit. — The  space  underneath  a  fire  box,  in  a  core  oven 
or  brass  furnace,  to  receive  the  ashes  which  fall  from  the 
grate. 

Bars. — The  framework  inside  the  cope  of  a  molding  flask, 
to  retain  the  molding  sand  in  position  while  lifting  or  hand- 
ling the  flask,  and  also  to  resist  the  pressure  of  metal  when 
casting. 

Batten. — A  piece  attached  to  a  thin,  flat  pattern  for  the 
purpose  of  strengthening  and  keeping  it  straight;  not  a  part 
of  the  pattern  nor  to  be  a  part  of  the  casting.  It  should  be 
marked  "stop-off,"  and  the  recess  formed  by  this  piece  in 
the  mold  should  be  filled  up  or  stopped  off  after  the  pattern 
has  been  removed  from  the  sand. 


216  FOUNDRY  PRACTICE 

^  Bed  charge. — The  first  or  lower  charge  of  coke  in  a  cupola, 
reaching  from  the  bed  or  bottom  to  a  point  above  the  tuyeres. 

Bedding  in. — The  process  of  molding  a  pattern  by  em- 
bedding it  in  the  sand  in  the  exact  position  in  which  it  is  to  be 
cast. 

.  Bellows. — An  instrument  for  forcing  air  through  a  tube. 
Used  in  foundries  for  the  purpose  of  blowing  away  loose  sand 
from  the  molds. 

J  Binders. — The  various  articles  used  in  loam,  core  sand, 
and  facings  for  the  purpose  of  holding  the  sand  together 
when  dry,  such  as  glue  water,  molasses,  linseed  oil,  flour, 
etc. 

I/  Blacking. — A  thin  facing  of  carbon,  consisting  of  pul- 
verized charcoal  or  plumbago,  by  which  the  fusible  ingre- 
dients of  the  sand  are  protected  from  the  intense  heat  of  the 
metal  when  casting.  Blacking  is  sometimes  applied  as  a 
powder  to  green  sand  molds ;  but  for  dry  sand,  loam,  or  skin- 
dried  molds  and  cores  wet  blacking  or  black  wash  is  used. 
Wet  blacking  consists  of  common  blacking  mixed  with  water 
thickened  with  clay  to  the  consistency  of  thin  paint.  Wet 
blacking  somewhat  hardens  the  surface  of  a  mold  when  dry. 

Black  lead. — See  GRAPHITE. 

Blast. — The  current  of  atmospheric  air  delivered  from  the 
blower  or  fan  under  pressure  through  the  blast  pipe  and 
tuyeres  into  the  cupola. 

Blast  gauge. — The  blast  gauge  is  a  device  to  determine 
the  amount  of  pressure  in  the  wind  belt  or  jacket  of  a  cupola 
while  in  operation.  This  instrument  is  a  form  of  mano- 
meter. 

v  Blast  pipe. — The  pipe  through  which  the  air  passes  from 
the  fan  or  blower  to  the  cupola. 

Blower.— A  box  with  revolving  wings  or  vanes  inside,  so 
constructed,  and  arranged  as  to  force  a  pressure  of  air  through 
the  blast  pipe  into  the  cupola. 


GLOSSARY  217 

v  Blow-holes. — Holes  occurring  in  castings,  due  to  air  and 
gas  in  the  metal  and  in  the  mold  when  casting.  Blow-holes 
are  the  result  of  insufficient  venting  and  of  moisture. 

Bott  stick. — A  stick  of  wood  or  bar  of  iron  with  one  flat 
end  on  which  to  place  a  ball  of  clay  in  stopping  the  flow  of 
iron  from  the  cupola. 

Bottom  board. —The  board  on  which  the  flask  rests  when 
in  position  to  cast.  It  may  be  of  iron  or  wood. 

Breast. — The  clay  front  built  in  the  opening  over  the 
spout  of  the  cupola  and  through  which  the  tapping  port 
is  made. 

Bricking  up. — Building  up  the  skeleton  of  a  loam  mold 
by  means  of  bricks  cemented  together  with  loam. 

Bull  ladle. — A  vessel  for  handling  molten  metal.  It  is 
placed  in  a  shank  and  is  carried  by  two  or  more  men. 

Burning  on,  or  casting  on. — The  process  of  mending 
cracked  or  broken  castings  or  of  adding  on  metal,  where  the 
casting  is  unsound  or  incomplete,  by  means  of  flowing  molten 
metal  over  the  part  to  be  treated  until  fusion  takes  place. 

Burnt  sand. — Sand  which  has  had  contact  with  molten 
metal.  The  sand  which  forms  the  face  of  a  mold  invariably 
becomes  burnt. 

Butting,  or  butt  ramming. — The  process  of  butting  or 
ramming  the  sand  with  the  flat  end  of  the  rammer. 

Camber. — The  curving  of  certain  types  of  casting  in  cool- 
ing, due  to  want  of  symmetry  in  their  sectional  forms,  by 
reason  of  which  one  portion  cools  off  more  rapidly  than  the 
other,  causing  distortion  of  figure  in  the  longitudinal  direc- 
tion. 

Carrier. — A  casting  which  is  attached  to  the  arm  of  a 
gear  molding  machine  and  to  which  the  tooth  block  is 
attached. 

Casting. — A  piece  of  metal  work  obtained  by  pouring 
molten  metal  into  a  mold. 


2l8  FOUNDRY  PRACTICE 

Casting  on. — The  same  as  burning  on. 

Changing  hook.— An  S  crane  hook  which  is  double  at  one 
end  and  which  is  useful  in  transferring  from  one  crane  to 
another. 

Chaplet. — Chaplets  are  iron  supports  to  retain  a  core  in 
its  proper  position  where  core  prints  can  not  be  used. 

Chaplet  block. — A  block  of  wood  rammed  in  the  sand  to 
receive  the  spike  of  a  chaplet  nail.  The  block  affords  the 
requisite  steadiness  to  the  chaplet  when  in  position. 

Chaplet  nails. — A  chaplet  with  one  end  flat  and  the  other 
a  sharp  point  to  be  driven  into  the  bottom  board  or  into 
a  block  of  wood  rammed  up  in  the  sand  which  forms  the 
mold. 

Charcoal. — Coal  made  by  charring  wood.  It  is  used  in 
drying  molds.  Oak  charcoal  pulverized  is  used  for  the  pur- 
pose of  blackening  molds. 

Cheek. — An  intermediate  part  of  a  mold  where  more  than 
two  parts  are  necessary. 

Chill. — A  metal  form  placed  in  a  mold  or  forming  a  portion 
of  the  mold  against  which  the  iron  is  poured  to  produce  a 
chilled  casting. 

Chilled  casting. — A  casting  whose  surface  is  hardened  by 
pouring  molten  iron  against  a  chill. 

v  Cinder  bed. — A  bed  or  layer  of  cinders  or  coke  placed 
below  a  pit  mold  for  the  purpose  of  carrying  off  the  gases  that 
pass  downward.  The  cinder  bed  is  connected  to  the  surface 
by  a  vent  pipe. 

Clamps — are  wrought  or  cast-iron  bars  whose  ends  form  a 
right  angle.  They  are  usefuLin  binding  together  the  top  and 
bottom  of  a  flask  while  pouring  the  metal. 

Clamping. — Placing  the  clamps  in  their  proper  position  on 
the  flask  when  the  mold  is  completed. 

Clay  wash. — A  mixture  of  clay  and  water. 

Coke  bed. — See  CINDER  BED. 


GLOSSARY  2Ip 

Cold  shots. — Small  globular  particles  of  metal  which  are 
formed  by  the  first  splashing  of  metal  in  a  mold  and  which 
harden  quickly  and  do  not  amalgamate  with  the  other  metal 
in  the  mold. 

Cold-shuts — are  produced  by  pouring  the  metal  too  cold 
or  too  slowly  into  the  mold  and  are  due  to  imperfect  amalga- 
mation of  the  metal  in  the  mold.  They  may  also  be  caused 
by  gases  in  the  mold,  arising  from  the  use  of  facing  sand  con- 
taining too  great  a  percentage  of  sea  coal. 

Contraction. — See  SHRINKAGE. 

Cope. — The  top  part  of  a  flask  or  mold. 

Core. — A  body  of  sand  in  the  mold  for  forming  interior 
openings  or  holes  in  the  casting. 

Core  barrel. — A  hollow  bar  or  pipe  on  which  a  cylindrical 
core  is  formed.  The  barrel  gives  the  core  strength,  and  also 
openings  through  the  sides,  affording  vent  for  the  gases  gener- 
ated in  casting  the  metal  around  the  core. 

Core  board. — A  board  whose  edge  is  profiled  to  a  sectional 
form  of  a  desired  core. 

Core  box. — A  box  in  which  a  core  is  to  be  formed  or  molded. 
Its  interior  shape  to  be  the  same  as  the  outside  form  of  core 
desired. 

Core  carriage. — A  carriage  upon  which  the  cores  are 
placed  after  being  molded  and  on  which  they  are  conveyed 
into  the  drying  oven. 

Core  irons. — Rods  or  bars  of  iron  rammed  up  in  a  core  to 
give  it  strength. 

Core  lathe. — A  frame  having  V's  or  bearings  in  which  to 
place  a  core  barrel  provided  with  a  crank,  on  which  barrel  a 
core  is  to  be  formed  and  trued  up  by  revolving  the  core  against 
a  sweep  which  forms  the  desired  shape  of  the  core. 

Core  mixture. — A  core  sand  dampened  and  mixed  with 
a  binder  in  such  proportions  that  when  dry  it  will  become 
hard. 


220  FOUNDRY  PRACTICE 

Core  oven. — An  oven  in  which  to  bake  or  dry  cores  after 
molding  them. 

Core  plate. — A  plate  on  which  cores  are  formed  or  placed 
while  drying. 

Core  print. — An  attachment  or  projection  on  a  pattern 
which  forms  a  seat  or  pocket  in  the  sand  in  which  the  core  is 
to  be  placed  in  the  mold  after  the  pattern  has  been  removed. 

Core  rope. — Ropes  or  strings  used  for  forming  vents  in 
crooked  cores,  from  which  rods  or  wires  could  not  be  with- 

/rawn  without  damage  to  the  core. 
Core  sand. — Any  sharp  sea  sand  or  nearly  pure  silica. 

Core  trestles. — Upright  standards  or  trestles  whose  tops 
are  provided  with  V-shaped  recesses  or  bearings  in  which  to 
place  the  ends  of  a  core  bar  or  barrel  while  revolving  to  sweep 
up  a  core. 

Core  wash. — See  BLACKING. 

Crane. — A  device  for  lifting  and  moving  heavy  weights  in 
a  foundry,  such  as  flasks,  weights,  and  ladles  of  molten  metal. 

Crane  ladle. — See  LADLE. 

*</  Crushing. — Compressing  the  sand  in  the  mold  by  too 
great  a  strain  on  the  clamps  after  the  pattern  has  been  with- 
drawn, causing  the  mold  to  crumble  and  sand  to  fall  into  the 
mold. 

Crystalline  fracture. — Where  the  face  of  the  break  shows 
a  coarse  formation  of  crystals. 

Cupola. — A  cylindrical  furnace  for  melting  iron.  A 
cupola  is  lined  with  fire-brick  and  provided  with  ports  or 
tuyeres  near  its  base  through  which  a  pressure  of  air  is 
forced. 

Cutting  over. — The  process  of  shoveling  over  the  sand  to 
obtain  an  even  mixture  and  temper. 

Daubing. — Lining  or  plastering  up  the  interior  of  a  cupola 
or  ladle  with  clay  or  molding  sand.  The  operation  is  per- 
formed with  the  hands. 


GLOSSARY  221 

Dowel. — A  pin  of  wood  or  metal  used  to  hold  the  parts 
of  a  divided  pattern  in  their  respective  positions  while  they  are 
being  rammed  in  the  sand. 

Draft. — The  allowance  or  slight  taper  made  on  a  pattern 
to  aid  in  its  removal  from  the  sand  after  being  rammed  up. 
The  portion  of  the  pattern  at  the  parting  line  of  the  mold 
must  be  larger  than  that  extending  into  the  cope  or  drag. 

Drag. — The  lower  part  of  a  mold  when  in  position  to  be 
cast. 

Draw. — The  casting  draws  when  the  shrinkage  causes 
depressions  of  the  surface  or  openings  in  the  interior.  See 
DRAWING. 

Drawback. — A  section  of  a  mold  rammed  up  separate 
from  the  drag  and  cope  and  parted  by  a  plate  or  piece  of 
cloth,  and  which  may  be  drawn  back  for  the  convenience 
of  the  molder  in  removing  the  pattern  or  in  patching  the 
mold. 

Drawback  plate. — The  iron  plate  on  which  a  drawback 
is  rammed  up. 

Drawing. — Removing  the  pattern  from  the  sand  after  the 
mold  has  been  formed,  also  increasing  the  depth  of  a  mold 
without  altering  the  dimensions  of  the  pattern  by  drawing  the 
pattern  a  part  of  the  length  upward  and  ramming  the  sand 
around  its  upper  portion. 

Draw  plate. — A  plate  attached  to  a  pattern  for  the  pur- 
pose of  receiving  the  rapping  iron  and  lifting  screw. 

Draw  spike. — A  tool  pointed  at  one  end  to  be  driven  into 
the  pattern  for  the  purpose  of  lifting  it  from  the  sand. 

Drop-out. — The  whole  or  part  of  the  sand  falling  out  of 
the  cope  of  a  mold  while  turning  over  or  closing  a  flask. 

Drying. — The  process  of  evaporating  moisture  from  a 
mold  by  means  of  hot  air  injected,  or  of  a  charcoal  fire  basket, 
or  by  baking  in  an  oven. 

Dry  sand. — Mixtures  of  sand  which,  after  being  dried  in 


222  FOUNDRY  PRACTICE 

an  oven  or  otherwise,  become  hard  and  better  resist  the 
strain  from  molten  metal. 

Dull  iron. — Iron  which  has  not  been  heated  to  a  proper 
temperature,  or  which  has  been  allowed  to  remain  in  the  ladle 
too  long  before  pouring.  Dull  iron  causes  seams,  cold-shuts, 
and  unsound  castings. 

Facing. — Any  material  used  to  mix  with  the  sand  for  the 
purpose  of  preventing  the  fusion  of  the  sand  and  the  metal. 
Pulverized  sea  coal  is  commonly  used. 

Facing  sand. — The  mixture  of  sand  which  forms  the  face 
of  the  mold. 

Fan. — An  apparatus  provided  with  revolving  wings  enclosed 
within  a  case  for  the  purpose  of  forcing  air  into  the  blast  pipe 
of  a  cupola. 

Feeder  head. — A  body  of  molten  metal  contained  in  a 
riser  or  opening  above  a  mold  for  the  purpose  of  supplying 
metal  to  the  mold  when  shrinkage  takes  place. 

Feeding. — Forcing  the  metal  into  the  mold  from  the  feed- 
ing head  during  the  time  it  is  liquid  by  means  of  an  iron  rod 
kept  in  motion  vertically  in  the  feeding  head.  It  is  some- 
times termed  "  pumping  "  a  mold. 

Feeding  rod. — A  wrought-iron  bar  used  for  the  purpose  of 
feeding  a  mold. 

Fin. — A  thin  projection  on  the  casting  at  the  parting  line 
of  the  mold,  caused  by  an  imperfect  joint. 

Fire-clay. — A  kind  of  clay  which  will  sustain  intense  heat 
and  which  is  used  in  furnaces,  cupolas,  and  ladle  linings. 

Flask. — A  box  or  frame  in  which  a  mold  is  formed.  A 
flask  must  consist  of  two  or  more  parts  and  may  be  made  of 
either  wood  or  metal. 

Flow-off  gate. — A  vertical  passage  through  which  the 
metal  flows  after  the  mold  has  been  filled.  Its  top  is  lower 
than  the  level  of  the  pouring  gate. 

Flux. — Any  material  used  in  a  melting  furnace  or  cupola 


GLOSSARY  223 

to  cause  the  slag  to  become  more  liquid  and  more  easily 
drawn  off  before  tapping  out  the  iron.  Limestone  is  com- 
monly used. 

Follow-board. — A  board  which  conforms  to  the  form  of 
the  pattern  and  defines  the  parting  surface  of  the  drag. 

Foundation  plate. — A  plate  of  cast  iron  placed  in  the 
bottom  of  a  mold  to  receive  the  spindle  to  maintain  a  sweep. 

Founding. — The  casting  of  metal  in  molds. 

Fusing. — The  iron  and  sand  are  said  to  fuse  when  a  hard 
coating  of  sand  adheres  to  the  metal  after  casting,  due  to  the 
heat  of  the  molten  metal. 

Gaggers — are  made  of  iron  in  the  shape  of  the  letter  L 
and  are  used  for  the  purpose  of  anchoring  the  sand  to  be  lifted 
in  the  cope  of  a  mold. 

Gangway. — The  passages  between  the  molding  floors  and 
leading  from  the  cupola.  The  gangway  is  usually  laid  with 
iron  plates  over  which  trucks  or  ladle  carriages  are  run. 
j  Gate. — The  terminus  of  the  runner  where  the  metal  enters 
the  mold.  The  opening  through  the  cope  left  by  the  gate 
stick  is  commonly  called  the  gate. 

Gate  cutter. — A  piece  of  thin  sheet  metal  bent  to  the 
shape  of  the  letter  U.  It  is  used  to  cut  the  runners  which 
conduct  the  metal  to  the  mold. 

Gate  stick. — A  wooden  pin  or  stick  used  by  the  molder  to 
form  the  opening  leading  from  the  pouring  basin  to  the  runner. 
It  is  placed  in  position  before  the  sand  is  rammed  in  the 
cope. 

Grab  hook. — Hooks  connected  by  short  chains  or  rods'  for 
the  purpose  of  attaching  loads  to  the  crane  hook. 

Graphite. — Carbon  in  one  of  its  conditions,  distinguished 
by  its  usually  crystallizing  in  foliated,  six-sided  prisms,  though 
often  massive,  by  its  softness,  by  its  metallic  lustre,  and  by 
leaving  a  dark  lead-colored  trace  on  paper.  It  is  often  called 
plumbago  or  black  lead. 


224  FOUNDRY  PRACTICE 

Green  sand. — Common  molding  sand  suitably  tempered 
to  form  molds  for  metal  without  subsequent  drying. 

Gutters. — Shallow  channels  cut  at  the  parting  of  a  mold 
for  the  purpose  of  receiving  the  vents  which  are  led  off  at  the 
parting  and  of  conducting  them  to  a  relief  vent. 

Hand  ladle. — See  LADLE. 

Hard  ramming. — Ramming  the  sand  in  a  mold  until  hard. 
Some  molds  should  be  rammed  hard  to  resist  the  pressure  of 
the  metal. 

Hatching  up. — Cutting  or  roughening  the  surface  of  a 
mold  for  the  purpose  of  better  holding  new  sand  which  may 
be  added  in  patching. 

Hay  rope. — Hay  twisted  or  spun  to  the  form  of  a  rope, 
used  to  wind  around  a  core  barrel  or  hollow  bar  in  striking 
up  round  cores  or  loam.  The  hay  holds  the  sand  or  loam  to 
the  bar  and  also  affords  escape  for  the  gases. 

Hot  metal. — Metal  which  is  in  its  liquid  state.  Light  and 
thin  castings  should  be  poured  with  hot  metal. 

Ladle. — An  iron  vessel  lined  with  fire-clay  and  used  in 
handling  molten  metal  from  the  cupola  to  the  mold.  Hand 
ladles  are  carried  by  one  man  and  bull  ladles  by  two  or  more. 
Crane  ladles  are  handled  by  the  crane. 

Leveling. — Making  a  bed  of  sand  level  by  the  use  of  parallel 
strips,  a  straight  edge,  and  a  level. 

Leveling  strips. — Parallel  strips  used  in  leveling  sand 
beds. 

Lifter. — A  tool  used  for  removing  loose  sand  from  the 
bottom  of  deep  molds. 

Lifting  screw. — An  iron  rod  with  a  screw  or  thread  cut  at 
one  end  and  an  eye  or  loop  at  the  other.  The  screw  may  be 
used  in  the  wood  pattern  and  the  thread  in  a  tapped  plate 
attached  to  the  pattern. 

Lift  off. — To  remove  a  portion  of  a  mold  after  ramming 
up. 


GLOSSARY  225 

Loam. — Loam  sand  is  a  mixture  of  sand,  clay,  and  venting 
material,  such  as  horse  manure,  which  gives  a  firm,  hard,  but 
open -grained  body  when  dry.  The  mixture  must  be  regu- 
lated by  the  class  of  castings  for  which  the  loam  is  to  be  used. 

Loam  board. — A  board  the  edge  of  which  is  profiled  to  a 
sectional  form  of  a  mold  which  it  is  to  strike  up.  It  is  swept 
around  a  vertical  bar  to  which  it  is  bolted. 

Loam  mold. — A  mold  constructed  of  loam. 

Loam  plate. — A  plate  of  iron  cast  in  an  open  mold  and 
studded  with  spikes  upon  which  the  brickwork  of  a  loam  mold 
is  built. 

Loose  piece. — A  portion  or  projection  made  detachable 
from  the  body  of  a  pattern  'for  convenience  in  molding. 

Melting  zone. — A  space  above  the  tuyeres  in  a  cupola 
where  the  greatest  heat  is  obtained. 

Mold. — The  matrix  or  reverse  form  of  a  pattern  made  in 
sand. 

Molding. — The  process  of  forming  a  mold  in  which  metal 
is  to  be  cast. 

Molding  machine. — Any  machine  by  which  the  operation 
of  molding  is  performed  or  the  drawing  of  a  pattern  is  made 
safe  and  expeditious. 

.Molding  sand. — Sand  used  for  the  purpose  of  forming  a 
moldTand  possessing  the  quality  of  resisting  the  pressure  of 
molten  metal  as  well  as  the  heat.  It  must  also  be  porous  or 
open  when  compressed  in  order  to  allow  the  free  escape  of 
the  gases  generated  by  the  heat  of  the  metal. 

Nowel. — The  bottom  portion  of  a  mold  when  in  position 
to  cast.  Commonly  called  drag. 

Old  sand. — Sand  which  has  been  used  for  the  purpose  of 
molding  until  it  becomes  old,  black,  and  burnt  from  contact 
with  the  molten  metal. 

Open  sand  molding. — Molds  formed  in  the  floor  of  the 
foundry  and  having  no  cope  or  covering.  Only  castings 


226  FOUNDRY  PRACTICE 

having  one  flat  side  or  surface  can  be  formed  this  way.  The 
mold  must  in  all  cases  be  perfectly  leveled. 

Parting  sand. — Sand  used  for  the  purpose  of  preventing 
two  parts  of  a  mold  from  uniting.  It  causes  the  sand  to  part 
when  the  flask  is  opened  after  ramming.  Sharp  sand  or 
burned  core  sand  is  commonly  used. 

Patching. — The  process  of  repairing  a  mold  after  the  pat- 
tern has  been  removed  from  the  sand. 

Pattern. — A  model  from  which  to  form  a  mold;  its  im- 
pression in  the  sand  forming  a  mold  in  which  to  pour  molten 
metal  to  form  a  casting. 

Peeling. — A  casting  is  said  to  peel  when  the  molding  sand 
and  iron  do  not  fuse.  After  the  casting  has  cooled  the  surface 
of  the  metal  is  left  smooth  and  free  from  sand. 

Pit  molding. — Forming  a  mold  in  a  pit  dug  in  a  foundry 
floor.  Light  pit  molding  is  usually  of  green  sand. 

Plate  anchor. — The  anchor  used  in  a  pulley  anchor  having 
plates  to  cover  the  surfaces  between  the  arms. 

Plate  molding. — Dividing  the  pattern  at  its  centre  and 
placing  each  half  on  one  side  of  a  parting  board  which  is  pro- 
vided with  pin-holes  corresponding  with  the  pins  of  inter- 
changeable flasks.  The  drag  and  cope  may  be  rammed  on 
opposite  sides  of  the  board,  and  after  the  board  has  been 
removed  the  flask  may  be  closed. 

Plumbago. — A  mineral  consisting  chiefly  of  carbon.  It  is 
used  for  blacking  and  for  facing.  It  is  properly  called  graph- 
ite, but  often  called  black  lead. 

Pouring. — The  emptying  of  the  molten  metal  from  the 
ladle  into  the  pouring  basin  or  gate  of  a  mold. 

Pouring  basin. — A  reservoir  or  basin  formed  on  the  cope 
of  a  mold  to  receive  the  molten  metal  and  from  which  it  flows 
into  the  gate. 

Pulley  anchor.— The  part  of  the  mold  of  a  pulley  between 
the  arms  and  the  face  of  the  cope, 


GLOSSARY  227 

Pulley  foot. — A  cone  or  pyramid  placed  in  the  anchor  of 
a  pulley  mold  for  the  purpose  of  ensuring  removing  and  re- 
placing to  the  same  position.  The  pulley  foot  may  be  sepa- 
rate and  placed  in  the  anchor  while  ramming,  or  it  may  be 
a  part  of  the  anchor,  as  in  a  plate  anchor. 
j  Rammer. — A  tool  used  for  the  purpose  of  ramming  the 
sand  in  the  flask  and  around  the  pattern.  The  rammer  is 
usually  made  of  iron.  One  end  is  called  the  pein  and  the 
other  the  butt.  The  pein  end  is  rectangular  in  section  and 
the  butt  end  is  round  and  flat. 

Rapping. — The  process  of  loosening  the  pattern  from  the 
sand  while  yet  in  the  mold.  A  bar  is  inserted  in  the  pattern 
and  is  rapped  sidewise  in  every  direction  until  the  sand  com- 
presses and  is  free  from  the  pattern,  after  which  the  pattern 
may  be  easily  withdrawn. 

Rapping  bar. — A  bar  of  iron  either  pointed  or  threaded 
at  one  end  to  be  inserted  into  a  pattern  for  the  purpose  of 
rapping. 

Rapping  hole. — A  hole  bored  in  a  pattern  or  in  a  rapping 
plate  let  into  the  pattern  to  receive  the  rapping  bar. 

Rapping  plate. — An  iron  plate  screwed  to  or  let  into  a 
pattern  having  a  hole  to  receive  the  rapping  bar. 

Reverse  mold. — A  dummy  mold  on  which  a  portion  of  an 
actual  mold  is  to  be  rammed. 

Riddle. — A  sieve  for  sifting  sand  for  the  purpose  of  mold- 
ing. 

Riser. — An  opening  from  the  mold  to  the  top  of  the  flask 
through  which  gases  may  escape  and  the  surplus  metal  rise 
above  the  upper  surface  of  the  casting. 

Runner. — A  channel  cut  in  the  sand  to  conduct  the  metal 
from  the  pouring  basin  to  the  gate. 

Sand  sifter. — A  mechanical  device  for  the  purpose  of  sift- 
ing sand. 


228  FOUNDRY  PRACTICE 

Scabbed  castings. — Scabbed  castings  are  those  on  the 
surface  of  which  rough  and  uneven  projections  appear. 
Scabs  occur  from  various  causes,  such  as  imperfect  vent- 
ing, improper  ramming,  unsuitable  material,  too  rich  facing 
sand,  excess  of  moisture,  etc. 

•*  Scrap. — That  which  is  of  no  use  in  its  present  form.  The 
old  castings  which  are  only  good  for  the  metal  in  them,  or 
castings  which  cannot  be  used,  are  called  scrap. 

Sea  coal. — Sea  coal  is  ordinary  bituminous  coal.  When 
pulverized  and  mixed  with  molding  sand,  it  is  called  cea-coal 
facing. 

j  Shrinkage. — Contraction  of  metal  while  cooling  after  cast- 
ing. 

Shrink-holes. — Openings  in  the  surface  or  in  the  interior 
of  a  casting  caused  by  the  shrinkage  of  the  metal  in  cooling. 

Sinking  head. — The  prolongation  upon  a  casting  verti- 
cally to  supply  metal  to  replace  shrinkage.  The  excess  length 
is  cut  off,  leaving  the  desired  casting. 

Skeleton  core  box. — A  frame  or  skeleton  in  which  to  form 
a  core  without  a  full  core  box.  Skeleton  core  boxes  are  com- 
monly used  in  forming  one-half  of  a  round  core  by  means  of  a 
strike  stick. 

Skim  gate. — An  arrangement  of  gates,  runners,  and  risers 
which  will  effect  the  separation  of  the  impurities  before  the 
metal  enters  the  mold. 

Skimmer. — A  bar  of  iron  usually  bent  to  the  shape  of  the 
letter  L  at  one  end  for  the  purpose  of  preventing  the  slag  and 
dirt  from  following  the  metal  as  it  flows  from  the  ladle  to  the 
pouring  basin  of  a  mold. 

Skimming. — The  holding  back  of  the  slag  and  dirt  on  the 
surface  oi  molten  metal  while  being  poured  from  the  ladle 
into  the  mold. 

Skin-drying. — The  process  of  drying  the  face  of  a  mold. 

Slag. — The  refuse  from  the  cupola,  caused  by  impurities 


GLOSSARY  229 

of  the  metal  and  fuel,  as  well  as  by  the  fused  compounds  of 
the  silica  and  alumina  in  the  lining  and  daubing. 

Slag  hole. — A  port  hole  in  a  cupola  slightly  below  the  level 
of  the  tuyeres  for  the  purpose  of  tapping  out  the  slag  before 
tapping  the  iron. 

Sleeking.— See  SLICKING. 

Slick. — A  tool  used  for  smoothing  the  surface  of  a  mold. 
An  ordinary  trowel  may  be  used  for  a  slick. 

Slicking. — Smoothing  and  finishing  the  surface  of  a 
mold  with  a  trowel  or  slicking  tool.  Sometimes  spelled 
sleeking. 

Sling. — A  device  made  of  iron  or  of  rope  for  the  purpose 
of  handling  flasks  or  weights.  The  sling  is  used  to  connect 
the  crane  to  a  weight  or  to  the  trunnion  of  a  flask. 

Snap-flask. — A  small  flask  used  in  bench  molding  having 
a  hinge  at  one  corner  and  a  latch  at  the  diagonal  corner. 

Soldiers. — Strips  of  wood  used  by  the  molder  to  strengthen 
or  to  anchor  bodies  of  sand. 

Socket. — The  base  for  supporting  the  spindle  in  a  sweep 
mold.  See  FOUNDATION  PLATE. 

Spongy. — A  casting  is  spongy  when  honeycombed  by 
blow-holes.  The  centre  of  a  casting  may  be  spongy  from 
shrinkage  of  the  metal  in  solidifying. 

Spout. — A  box  or  gutter  lined  with  clay  to  conduct  the 
molten  metal  from  the  tapping  hole  to  the  ladle. 

Spray  can. — A  can  fitted  with  a  blow-pipe  or  bellows  so 
that  the  liquid  in  the  can  may  be  forced  out  in  a  spray  or 
mist. 

Sprue. — The  casting  formed  in  the  gate  of  a  mold. 

Staking. — The  setting  of  the  cope  on  a  pit  mold  by  means 
of  stakes. 

Stopping  off. — The  process  of  filling  up  a  portion  of  the 
mold  which  is  not  desired  to  be  cast. 

Stopping-off  piece. — A  piece  used  as  a  guide  or  template 


230  FOUNDRY  PRACTICE 

in  stopping  off.  A  stop-off  piece  is  a  duplicate  of  the  desired 
casting  at  the  point  stopped  off  on  the  pattern. 

Stopping  over. — Filling  up  with  sand  the  space  over  a 
core  placed  in  a  print  pocket. 

Straining. — The  distortion  of  a  mold  by  the  pressure  of 
the  metal,  usually  caused  by  insufficient  ramming  of  the 
sand. 

Strike  stick. — A  straight  edge  or  form  beveled  at  its  edge 
for  the  purpose  of  cutting  the  sand  or  loam  in  building  up  a 
mold  or  core. 

Stripping  plate. — The  plate  which  holds  the  sand  in  place 
while  the  pattern  is  being  drawn. 

1  Strong  sand. — Molding  sand  is  called  strong  when  it  con- 
tains clay  and  when  upon  drying  it  becomes  hard  and  will  not 
crumble. 

Swab. — A  substitute  for  a  brush  for  dampening  sand  in  a 
mold  or  around  a  pattern  before  it  has  been  removed  from  the 
sand.  Swabs  are  usually  made  of  hemp. 

Swabbing. — The  dampening  with  a  swab  of  the  joint 
edges  or  interior  sections  of  a  mold  for  the  purpose  of  strength- 
ening the  sand  and  causing  it  to  be  more  plastic  and  coherent. 

Sweep. — A  board  having  the  profile  of  a  desired  mold.  A 
sweep  must  be  attached  to  a  spindle  and  revolved  around  the 
spindle  to  give  the  mold  the  proper  form. 

Tap  hole. — The  hole  through  the  breast  of  a  cupola  through 
which  the  metal  flows. 

Tapping. — Opening  the  port  of  a  foundry  cupola  for  the 
purpose  of  allowing  the  metal  to  flow  into  the  ladle. 

Tapping  bar. — A  long  bar  of  iron  pointed  at  one  end  and 
having  a  loop  at  the  other  to  serve  as  a  hand  hold.  It  is  used 
for  the  purpose  of  opening  the  tap  hole  in  a  cupola  to  allow 
the  metal  to  flow  out. 

Tempering  sand. — The  process  of  dampening  and  mixing 
the  sand  preparatory  to  ramming  a  mold. 


GLOSSARY  231 

Test  bar.— A  bar  of  iron  cast  for  the  purpose  of  testing 
the  strength  of  the  metal. 

Trammel. — Another  name  for  a  beam  compass. 

Traveling  crane. — An  apparatus  arranged  on  overhead 
tracks  and  so  constructed  as  to  move  a  load  in  any  direction. 

Trowel. — A  tool  similar  to  a  mason's  trowel,  used  in  slick- 
ing, patching,  and  finishing  a  mold.  Trowels  are  of  various 
shapes  and  sizes. 

Tucking. — Compressing  the  sand  with  the  fingers  under 
flask  bars  or  around  gaggers  or  soldiers  where  the  rammer 
can  not  be  used. 

Turning  over. — The  operation  of  inverting  the  drag  of  a 
mold  with  the  pattern  in  the  sand.  The  top  and  bottom  are 
covered  with  boards,  clamped  up,  and  turned  over. 

Turn-over  board. — The  board  upon  which  a  pattern  is 
placed  while  ramming  up  the  drag  of  a  mold. 

Tuyeres. — The  openings  which  admit  the  air  blast  to  the 
interior  of  a  cupola  or  blast  furnace. 

Vents. — Any  means  provided  for  the  escape  of  "gases  or  of 
steam  generated  by  contact  of  molten  metal  with  cores  or 
molding  sand. 

Vent  gutter. — A  groove  or  an  opening  cut  in  the  sand  to 
conduct  the  gases  away  from  the  vents. 

Venting. — The  process  of  making  vent  holes  or  openings 
in  the  mold  by  means  of  a  vent  wire,  or  otherwise  to  allow  the 
gases  to  escape  while  casting. 

Vent  strings. — Strings  used  for  the  purpose  of  venting 
crooked  cores  when  wires  or  rods  could  not  be  employed 
without  damaging  the  core.  Sometimes  wax  strings  are  used 
and  melted  out  in  drying  the  core. 

Vent  wire. — A  small  rod  or  wire  used  in  forming  a  vent. 

-Weak  sand. — Sand  having  a  very  small  percentage  of  clay, 
thus  having  but  little  strength  at  the  usual  temper  and  hard- 
ness. 


232  FOUNDRY  PRACTICE 

Wedges. — Small  V-shaped  pieces  for  the  purpose  of  block- 
ing under  a  clamp  or  over  a  chaplet.  Wedges  may  be  of 
wood  or  iron. 

Wet  blacking. — See  BLACK  WASH. 

Wind  jacket. — The  chamber  surrounding  a  cupola  into 
which  the  air  is  forced  from  the  blast  pipes  and  from  which 
it  enters  the  tuyeres  leading  to  the  cupola. 


INDEX 


Bedding  in,  15. 

Blow-holes  and  shrink-holes,  in. 

Brass,  molding  of,  199;    founding  of,  202;    melting  furnace  for,  202; 

same  for  fuel  oil  or  gas,  206. 
Burning  on  or  casting  on,  112. 

Castings,  feeding  of,  95;  chilled,  172;  malleable,  176;  cleaning  of, 
180;  steel,  195. 

Cast-iron  alloys,  208,  209. 

Chaplets,  described,  100;   setting  and  wedging  of,  103. 

Clamping  or  weighting  of  cope  and  cores,  107. 

Columns,  molding  of,  44. 

Compressed  air,  185. 

Coping  out,  1 1 . 

Cores,  setting  and  venting  of,  21,  98;  cover,  37;  described,  123;  ram- 
ming of,  125;  wires  and  rods  for,  125;  baking  or  drying  of,  128; 
pasting  of,  127;  nearly  submerged,  146. 

Core  anchors,  144. 

Core  barrel,  136. 

Core  box,  138;  skeleton  core  box,  139. 

Core- making  machines,  150. 

Core  mixtures,  134;   core  blacking  mixtures,  135. 

Core  ovens,  129. 

Core  plates,  143. 

Cupola,  preparing  of,  155;  tapping  out  and  stopping  up  of,  160. 

Flasks,  74- 

Fly-wheels,  methods  of  casting,  64. 
Follow-board,  115. 
Foundry  blowers,  169. 
Foundry  ladles,  166. 

Furnace  cupola,  151;  reverberatory,  162;  brass  melting,  202;  same  for 
fuel  oil  or  gas,  206. 

Gaggers,  88. 

Gears,  molding  of,  48. 

233 


234  INDEX 

Hay-rope  machines,  136 

Loam  mixtures,  67 
Loam  molding,  66. 

Molding,  bench,  114;  plain,  i;  with  divided  pattern,  8;  open  sand, 
18;  of  columns,  44;  of  gears,  48;  pit,  59;  loam,  66;  brass,  199. 

Molding  machines,  115. 

Molds,  venting  of,  19;  parting  of,  82;  gating  of,  83;  patching  of,  92; 
stopping  off  of,  94;  crushing  of,  no;  match  for  a,  115;  dry  sand,  53; 
finishing  dry  sand,  55;  blacking  dry  sand,  55;  drying  dry  sand,  56. 

Nailing  or  rodding,  91. 

Pneumatic  chipping  hammer,  188. 
Pneumatic  crane,  185. 
Pneumatic  hoist,  185. 
Pneumatic  molding  machine,  185. 
Pneumatic  sand  rammer,  188. 
Pneumatic  sand  sifter,  185. 
Pneumatic  shaker,  189. 
Pouring  basins,  88. 
Pulley  anchors,  40. 
Pulley  rings,  38. 

Risers,  85. 

Sand,  molding,  69;   tempering  of,  69;    cutting  over  of,  69;    riddling  of, 

71;  facing,  72;  ramming  of,  77;  parting,  83. 
Sand-blast  machine,  189. 
Sand  crusher,  194. 
Sand  mixers,  194;  centrifugal,  194. 
Sand  sifter,  rotary,  194. 
Shrinkage,  in. 
Skim  gates,  86. 
Soldiers,  90. 
Steel,  casting  of,  195. 
Sweeps  and  spindles,  60. 

Three-part  work,  30. 
Tools,  molders',  76. 
Tumbling  barrels,  181. 

Vent  gutters,  147. 


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